1. Introduction

This article is intended to better inform specifiers and users about automatic data collection and the advantages of bar coding and thermal print technology utilized to facilitate this process. Compiled by Zebra Technologies Corporation, the world leader in barcode print solutions, it provides an objective and informative insight into this valuable technology.

While thermal print technology may not be the solution to all of your labeling problems, it is an excellent choice for many situations, and should be well understood by every specifier or potential user attempting to implement a barcode system.

This information will explain the principles of thermal print technology, discuss when its application is most appropriate in relation to the alternative technologies available, and detail Zebra’s role in the industry as a leading supplier of barcode printers, software and labeling supplies.

2. Bar Coding Basics

Automatic Data Collection and the Advantages of Bar Coding

What once seemed to be simply an odd little zebra stripe that began appearing on a few retail, food industry related goods in the early 1970’s has evolved into an effective and widely used productivity enhancement tool. Bar codes are a fast, easy and accurate data entry method used in the process known as automatic data collection. Bar coding enables products to be tracked efficiently and accurately at speeds not possible using manual data entry systems. The primary benefit of this process is that it is truly automatic, occurring instantaneously as a transaction or process takes place, commonly referred to as real-time data capture and exchange within the industry. Improved accuracy is yet another benefit. Studies show that the entry and read error rates when using automatic data collection and bar code technology is approximately 1 error in 1 million characters versus 1 error for every 300 characters in manual key entry.

The IBM PC explosion in the early 1980’s, served as the catalyst to promote the widespread usage and application of bar coding for automatic data collection. Over the past 20 years, bar coding has become a virtual necessity for the collection and processing of information in a quick and timely manner enabling companies, in every conceivable industry, to maximize and dramatically increase their productivity and overall efficiency. Bar codes enable managers to track information and activity as it occurs allowing their decisions to be dictated by more concrete, current information. The traditional manual key and entry process of information compiled on sheets of paper, by comparison, does not provide real-time data entry capability as the data being entered usually reflects events that occurred in the past.

Yet, despite the advantages of automatic data collection via bar coding, there is still an element of mystique and a stigma of high implementation cost associated with the technology that intimidates many people. With a better understanding of bar coding, the requirements for automatic data collection and its common application uses, we hope to demystify and eliminate any apprehensions you may have and shed light on the tremendous potential for the implementation of this technology in the world around you.

Bar Code Construction

Bar coding is a type of morse code used to encode or put information into a universally recognized code language in the form of a bar code symbology. Encoded data can consist of a part number, serial number, supplier number, quantity, transaction code, or other type of data. A number of bar code standards have been developed and refined over the years into accepted languages called symbologies. Numerous bar code trade associations, like (ANSI) American National Standards Institute, (HIBC) Health Industry Bar Code Council and (AIAG) Automotive Industry Action Group, have subsequently been established to regulate the use of bar code symbologies in accordance with accepted industry standards and specifications, as dictated by an industry.

Bar code symbologies come in two basic varieties. They can be either linear or two dimensional in their configuration. A linear barcode symbology consists of a single row of dark lines and white spaces of varying but specified width and height, as indicated by the example below.

Similarly, a 2-Dimensional symbology can be configured into a stacked or matrix format. Two dimensional bar codes are special rectangular codes which ‘stack’ information in a manner allowing for more information storage in a smaller amount of space.

The amount of data that can be encoded in a linear barcode symbology is more limited than that of a 2-D symbology. A 2-D matrix symbology of 1 x 1inch diameter, for example, can encode and store the entire US Constitution! Hence, the power of barcode technology in maximizing information storage within limited space.

In addition to symbology standards set by the various trade associations, there are several other related types of compliance standards used in manufacturing and distribution operations. These include:

Application Standards
An application standard is a set of policies and procedures that govern an application within an operation. Most operations have a defined set of rules to manage the material flow and manufacturing processes in their operation. These rules can be defined as an application standard.

Product Identification Standards
Product identification standards place a specific policy on how to mark products and what information must be made available to consumers purchasing those products.

Sample – Product Identification Standard

Label Standards
Label standards (also referred to as compliance labeling within the industry) have been created for commercial applications so trading partners can easily communicate and conduct business transactions at a higher level of efficiency.

Sample – Compliance Label Standard

Depending on the specific bar code application, conformance to one or more of these standards may be required.

Bar Coding Requirements

To establish a basic bar code system for automatic data collection, four primary components are required. They are – a bar code printer, a label for item tracking, scanning equipment for data collection and an external database for bar code data capture and relay.

Component 1 - The Bar Code Printer
The bar code printer provides the first vital component part in tracking information by generating the bar code label utilized in item tracking. A variety of technologies and methods exist to print a bar code label which will be discussed in greater detail in the next section, entitled "Available Bar Code Print Technologies".

Component 2 - The Bar Code Label
Automatic identification is the essential first step in a barcode system which is accomplished by attaching a barcode label to an item for tracking. An item label can contain any combination of text, graphic or bar code information, yet it is the bar code symbology that facilitates and promotes the item tracking process.

Component 3 - Scanning Equipment for Data Collection
The data collection phase occurs through the use of scanners that instantly and accurately read, capture and decipher the information contained in the barcode label. Scanners read information much faster and more reliably than humans can write or type. Thus, significantly reducing the rate or likelihood of error. Scanners also act as decoders deciphering the information contained in the barcode and converting it into a signal that can be understood by a computer system attached to a scanner. Note: Print quality is of utmost importance when printing bar codes so that the scanner has the ability to read them. Poor quality bar codes that do not scan can result in large fines or penalties that can deteriorate customer relations between a vendor and supplier.

Component 4 – Data Capture via an External Database
The fourth and final component to establishing a bar code system is the external database. Existing barcode applications commonly rely on the availability of external data computer systems to effectively identify a unique bar code with pertinent information about the article from a related database. The computer mainframe collects and interprets the data transmitted from the scanner and links the bar code reference point information to a detailed data file on that item. Such data files commonly contain various information on the item, including but not limited to, a detailed product description or price and inventory quantity, to enable transactions and activity to be effectively monitored in real-time. Without the advent of this external database, the bar code itself has no useful meaning or problem solving significance.

Note: Zebra’s corporate strengths are based heavily on components one and two listed here.

Key Benefits of Bar Coding

Implementing a bar code system in one’s facility offers tremendous advantages when coupled with the appropriate computer hardware and software of an external database. The most compelling advantages of barcoding and automatic data collection are:

Accuracy
Bar coding increases accuracy by reducing the likelihood of human errors from manual entry or miscommunication from misread or mislabeled items. Here again, bear in mind that print quality is of utmost importance to ensure that the scanner has the ability to read the bar code. Without this capability the accuracy and productivity gains of bar code technology are virtually non-existent.

Ease-of-Use
Bar codes are easy-to-use provided the appropriate hardware and software aspects are in place to maximize the process of automatic data collection.

Uniform Data Collection
Diverse compliance standards and standardized bar code symbologies ensure that bar code information is captured and relayed in a fashion that is universally understood and accepted.

Timely Feedback
Bar coding promotes timely feedback in that data is captured in real-time as it occurs enabling decisions to be made from current information.

Improved Productivity
Bar codes improve productivity in that many manual activities and tasks become automated enabling personnel resources to be utilized in other ways to increase the efficiencies of scale within an organization. Bar coding further enables manufacturing processes to be monitored and tracked more closely to improve the company’s overall quality standards.

Increased Profitability
The increased efficiencies (e.g. improved workflows, reduction in error rates and resultant happier customers) that bar coding promotes enables companies to save costs and substantially improve their bottom line.

Note: The return on investment for an automated data collection system is typically one year, and often substantially less.

Common Bar Code Applications

Where was the last time you saw a barcode or witnessed an automatic data collection transaction???

Your exposure to the world of bar coding and auto identification is likely to be more frequent than you might think. Bar coding and automatic data collection are processes that occur in and around us every day, without us consciously ever really thinking about it or taking direct notice of it. Consider the convenience it provides most readily in the retail or grocery industry to expedite one’s check-out procedure, or within the package delivery industry to track one’s package throughout its transport cycle.

In retail applications, labels adhered or attached to a product or item of clothing contain barcodes which are read by a scanner during checkout and interpreted by a computer. The computer recognizes the barcode’s data bit reference and is able to link the item to its sales price and description contained in the store’s mainframe database. This product information is reflected, not only, on your sales receipt, but is automatically linked to the store’s inventory tracking system which knows to deduct the quantity of the item purchased from the stores current level of inventory. This entire process occurs in a matter of seconds with only minimal data entry required by the checkout person in the form of quantity purchased – e.g. one or more.

Similarly, in a package delivery scenario, e.g. common carriers such as UPS^® or FedEx^®, the barcode label enables the package to be tracked as it passes through diverse sorting hubs en route to its ultimate destination. Throughout the package’s journey, each sorting hub scans the package to register its receipt before passing it onward. Thus, if the package’s arrival is ever delayed or misplaced, it can usually be tracked by its bar code tracking number to the exact point in the process where it may have stalled.

In addition to the retail and packaging industry, barcode data collection is used in a variety of industries, including but not limited to manufacturing, healthcare and automotive. Generally any industry or company can utilize bar coding to track and improve their current processes and operations. Some of the most common bar code applications referenced in the industry are:

Shipping & Receiving Compliance Labeling
Compliance labels utilize bar codes to facilitate and expedite shipping and receiving process functions between one’s suppliers and/or vendors. As a purchase order is received, the operator scans the bar code label and keys in the quantity that has been received into a hand-held portable data terminal which uploads this information to the computer mainframe. The mainframe can then point out product shortages that are double-checked on the spot rather than after an item has been moved or partially used. Similarly, as items are loaded in preparation for shipping, they are scanned enabling shortages or misloads to be detected immediately. As items are stored into inventory, the computer, thus, immediately registers the stock quantities as being available for picking to satisfy an upcoming order.

NOTE: Compliance label specifications vary depending on the customer. Any shipment not in accordance with a client’s specified compliance labeling requirement may be rejected and can result in a monetary fine, depending on the frequency and extent of the occurrence.

Inventory Control
Bar codes are frequently used for inventory control to track an item’s location and turnaround. When an item is either removed or entered into inventory its Product Description, Lot #, and Location are scanned from the shelf label by a portable data entry terminal which communicates this information back to the company’s computer mainframe via radio frequency. The quantity of product removed from inventory is entered separately (by the user) into the portable data terminal for relay to the mainframe so that the current inventory level is also registered within the mainframe. Product re-order points within the computer mainframe are set-up to recognize when an item needs to be replenished via the release of a Purchase Order to a given supplier.

Work-in-Process
Work-in-process labeling is frequently used in manufacturing facilities to monitor each phase in a manufacturing process to ensure consistent quality and output. With on-line or portable readers, scanning of a routing sheet with bar codes on them as parts or sub-assemblies are completed, enables work-in-process costs and manufacturing progress to be tracked.

Labor or Assembly Tracking
Similar to work-in-process, bar codes for labor tracking of a manufacturing process ensure the consistent quality and output of a job. Consider the following example: In a custom assembly, a terminal leads the operator in what to assemble. As the operator scans each part or sub-assembly added, the computer can monitor it for correct specifications. Should a manufactured part be found faulty, it can then be tracked back to the exact point and/or person responsible for the error.

Time and Attendance
Time and attendance is yet another popular application for bar codes. An employee badge with a bar code can be read into a computer terminal at clock-in and clock-out stations to provide attendance data to a computerized payroll program.

Asset-Tracking
Bar codes can help companies to track their assets by way of equipment or hardware that they may temporarily loan out to someone. A bar code placed on a rental video, for example, is scanned at checkout along with the borrower’s ID card enabling the item to be tracked while it is on loan.

Warehouse Picking
Involves a computer that downloads a list of items to a portable data terminal that instructs a warehouse worker to pick those items associated with a specific order. As locations are reached or items are picked, the bar codes are scanned and the terminal compares what was scanned to ensure that the right location or item is being picked. After picking the order, the worker goes back to the terminal to upload the data to the computer mainframe and to receive his next order of instructions for picking.

The afore-mentioned applications are examples of popular manufacturing related uses for bar coding. It is important to remember, however, that text and bar code labels have a multitude of traditional and/or specialized usage capabilities outside of the manufacturing realm as well.

3. Assessing the Labeling Application

When faced with a labeling or bar coding problem, it is often human nature to gravitate toward a familiar technology or approach in the solution. Dot matrix printer users, for example, may initially consider using a dot matrix printer for the task. Those most familiar with ink jet or laser printers may first design a laser or ink jet printer into their bar code system. This approach can be a valid first step as it provides a benchmark for comparison of performance and cost.

However, to ensure maximum efficiency, reliability and good design sense, a second design stage is required. That is, to carefully assess the labeling application and to explore the available bar code printing technologies that offer the best performance and cost effectiveness for that application. In order to be successful with this approach, the user and/or specifier must thoroughly understand the labeling application and the benefits and limitations of each of the alternative, available print technologies.

In assessing the labeling application, numerous details must be taken into consideration, including:

Outlining the tracking, operating requirements & sequence of events
Ask yourself and outline what task(s) require(s) automating, specifically through the use of a bar code label? What specific purpose will the label be set up to do? What process or steps will the label be required to go through? How will the label be applied, read, used, etc? How long does the label need to adhere (permanent versus semi-permanent) and last (long-life versus short-term)? What environmental conditions (heat, cold, moisture, humidity, chemical bath, blood or direct sunlight) might the label be exposed to?

Understanding what compliance standards may apply
What industry compliance label standards will likely dictate conformance issues concerning label content? Do I have any large end-users or suppliers who desire label formats relating to a specific compliance standard which must be adhered to?

Determining label content and estimated production volume requirements
Based on these compliance and tracking requirements, you must then assess what your daily, monthly and worst case scenario label volume usage requirements are? Do they justify the cost of off-site label supply printing or on-site demand printing?

Off-site versus On-demand Printing
Perhaps the most important factors in deciding whether to make or buy bar code labels are how quickly the labels are required, where the information for the label is coming from, and how often it will change. Label printing bureaus are best used for labels that are identical, constant, or contain data that is known in advance. Print bureaus can produce labels with serial numbers on them, in incrementing/decrementing sequences, or other related simple variable data. Most will also require two or three days to deliver the labels requiring some advanced planning to ensure that an adequate supply of labels remains on-hand.

When labeling unique items, where the label has to be matched to the object it is to identify, a print bureau may not be practical, particularly for large quantities of labels without an obvious sequence. Here, the difficulties of applying the label to the correct object may preclude the use of a print bureau and make a good case for the use of a demand printer. Demand label printing is also a must when labels containing large amounts of variable data or when the information is only available, at or just before, the time the label is to be applied.

Analyzing one’s budget constraints / criteria
Finally, one’s budget criteria must be analyzed. Specifically, what equipment, materials and/or personnel resources do I need to accomplish this task? What installation, operating and/or maintenance costs are involved? What are my warranty/service coverage options and supplies investment costs using a given print technology? Based on my label volume and maintenance costs, how quickly can I anticipate a return on my investment (ROI)? Do I have management support for such a project?

Based on your answers to these questions, you are now ready to choose a print technology and resultant printer from those available on the market with the desired options and suitable print speeds to meet your specific application needs.

4. Available Print Technologies

Some of the most popular choices for bar code printing are dot matrix, ink jet, laser and thermal printing. These print technologies each relate to Component 1 of the barcoding requirements mentioned earlier in section 2. To understand how each technology varies in execution and strength, let us take a moment to review each print method in detail assessing their respective strengths and weaknesses.

Dot Matrix Printing
Dot matrix print technology is one of the oldest techniques used for on-site label printing. The typical dot matrix bar code printer is a modified line printer requiring pin feed paper stock. Solenoid driven needles impact an ink coated nylon ribbon, transferring ink onto the paper or label. The image is built up dot-by-dot in a matrix as the needle and paper are moved relative to one another.

Advantages

Dot matrix printers are readily accessible and inexpensive to purchase.

They can print on virtually any type of form, check or document and can print on wide-web, multi-part (carbon) forms.

Dot matrix printers use multi-pass ribbons which can result in reduced overall cost for ribbons and the label material.

Limitations

Dot matrix printers print low to medium density bar codes that may not meet certain end-user guidelines. The dot size on the matrix printer limits the narrow element size and density of the barcode. The following example, compares sufficient dot overlap versus unacceptable dot overlap on a dot matrix printer used to print bar codes.

Continuous ribbon re-use on dot matrix printers requires continuous monitoring of ribbon condition to ensure adequate bar code contrast. Ribbon ink that has become exhausted can also produce an image that is inadequate for scanning, resulting in a low read rate and high error rate.

Ink saturation can result in paper "bleed" which can cause image distortion.

A dot matrix printed label is only as durable as a photocopy of paper. They commonly cannot produce chemical or water-resistant labels.

Printing of single, individualized labels results in significant waste. The design of the matrix printer’s print carriage, sitting far below the media, also does not enable one to adequately maximize one’s label space.

Dot matrix printing offers NO graphic print capability.

Print speed is greatly reduced when printing bar codes if greatest ink deposit and best print quality is desirable.

Ink Jet Printing
Ink jet printing is a common direct marking process and a favorite on high speed production lines. Ink droplets are selectively deflected between a moving product and an ink return channel. Ink jet printing is frequently used for coding products and cartons with human readable data and lot codes at very high speed and for case coding of cartons with bar codes.

Advantages

Common direct marking process on a product or carton that involves only one step compared to label printing which requires two steps: printing a bar code label and adhering it to the product.

A favorite on high speed production lines due to its "mark-on-the-fly" capability. "Mark-on-the-fly" being an affectionate term to describe this print process within the industry.

Used primarily for industrial use amongst large conglomerate organizations due to the affordability issue and high product volumes.

Limitations

Costly system installation designed for high volume of product labeling – not for individual or small batch label bar code printing.

Routine maintenance and supervision required to ensure consistent print quality and to prevent ink jet "clogging".

Limited dot placement accuracy and bar code density due to ink splatters and product being in continual motion.

Material to print on is restricted due to the advent of ink bleed on some materials.

Poor contrast of bar codes on corrugated box materials due to their dark backgrounds.

Properly matched scanning devices must be chosen to ensure bar code reliability.

Laser Printing
The laser printer works much like a photocopier projecting controlled streams of ions onto the surface of a print drum resulting in a charged image. The charged image then selectively attracts toner particles, transferring the image onto the paper substrate by means of pressure. The pressure from the printhead and drum then fuse the image to the paper, creating the image.

Advantages

Laser printers are good at producing bar code labeled documents on plain paper.

They can print high quality text and graphics on paper documents and can double as a document printer when not being used to print bar codes.

Bar code density is also quite high on laser printers resulting in a scannable code at virtually any wavelength using an infrared scanner.

Limitations

Laser printers are not well suited for industrial labeling applications or individual product labeling applications. Here, they prove inadequate and wasteful as it is impossible to produce single or small labels. (A minimum of a ½ a page of media is typically required for the printer to maintain control of the sheet. Unless the label is at least that size or multiple labels are needed at once, the remainder is wasted).

Laser printer labeling adhesives must be carefully selected to ensure stability under the heat and pressure of the fuser. Otherwise, it may extrude onto the printer mechanism, where it will capture stray toner or "curl" at the edges. Because of the pressures used in the laser printer image transfer process, many laminated label materials are not compatible with this technique. Those materials that are compatible may not always be available in sheet form for the laser printer to be able to print on.

A laser printed label is only as durable as a photocopy of paper. They commonly cannot produce chemical or water-resistant labels with the image longevity of a thermal printer.

Cost of laser toner cartridges for bar code printing is significant and can be costly. A 5% black density, for example, is commonly required for standard word processing versus a 15-30% black density for bar code printing. Bar code printing on a laser, therefore, is 6 x’s more expensive than standard word processing printing!

Direct Thermal Printing
Direct thermal printing is an old technology originally designed for low cost copiers and fax machines that utilizes chemically coated paper. It has since been transformed into a highly successful technology for bar coding. The thermal printhead is typically a long linear array of tiny resistive heating elements (about 100 to 300 per inch) that are arranged perpendicular to the paper flow. Each thermal printhead element locally heats an area on the chemically coated paper directly under the print element. This induces a chemical reaction which causes a black dot to form in that area. The image, itself, is formed by building it from dot rows as the media passes underneath the active edge of the printhead.

Advantages

Direct thermal printing is an excellent choice for many bar code applications because of the consistent, sharp edge image print quality that they can generate.

Direct thermal is ideal for applications with a short shelf life requirement – meaning the label is not required to last very long. Many packaging companies utilize direct thermal technology since the address and package tracking labels only need to last long enough to reach their destination which is typically accomplished in a few days.

Direct thermal printers provide simplicity and environmental economy with re-cyclable materials available.

Direct thermal printers are simple to operate compared to most other print technologies – no ribbon or toners to replenish or monitor.

Low, long-term maintenance cost compared to comparable technologies.

Enables batch or single label print capability with virtually no waste.

Direct thermal is durable compared to other comparable print technologies.

Office and/or limited industrial application usage, though more limited in application than thermal transfer due to its shorter image longevity.

Limitations

Direct thermal printing is extremely sensitive to environmental conditions – e.g. heat and light (fluorescent and/or direct sunlight).

Direct thermal paper remains chemically active after printing. Because of this, all thermal paper materials used – labels, tags or ticket stock – are top coated to resist UV light exposure, chemicals and minimal abrasion.

Thermal Transfer Printing
Thermal transfer printers use the same basic technology as direct thermal printers, but with the elimination of chemically-coated media material in favor of a non-sensitized face stock and a special inked ribbon. A durable, polyester ribbon film coated with a dry thermal transfer ink is placed between the thermal printhead and label. The thermal printhead is used to transcribe the ink onto the label surface, where it cools and anchors to the media surface. The polyester ribbon is then peeled away, leaving behind a stable, passive image

Advantages

High contrast, crisp image bar code print quality with a durable, long-life and archival image stability.

Ideal for batch or individual label print capability – with virtually no waste.

Low, long-term maintenance cost compared to comparable technologies.

Maximum readability and IR scannability.

High contrast text, graphic and bar code print capability.

Durable for operation in office or industrial applications.

Capable of printing on an unlimited variety of media stock – except multi-form.

Limitations

Cannot print on media without use of ribbon – resulting in higher supply costs over direct thermal which, by comparison, only requires media to operate and no ribbon.

Single pass thermal transfer ribbon can be wasteful if little is printed on it.

Ink transfer ribbon is a poor candidate for re-cycling

To obtain optimum print quality in thermal transfer, the ribbon and media substrate MUST be compatible. Otherwise, the heat from the printhead could melt the ribbon onto the label causing internal printer problems.

BAR CODE PRINT TECHNOLOGY MATRIX

5. When to Select Direct Thermal
or Thermal Transfer

For most engineers involved in bar code system automation deciding where a bar code printer is appropriate is a straightforward task. But specifically, when should a thermal printer be considered?

Direct thermal or thermal transfer printers can be specified for use in applications when any of the following criteria are specified:

A point-of-application system is required
Point-of-application refers to the requirement for a label to be generated at the exact time and location where it is to be applied to the product in question. In a manufacturing process, point-of-application labels are frequently required to label the product for product identification purposes or to label the product packaging in preparation for shipment.

Individual and / or batch printing of labels with variable data is frequently produced
Thermal printers are ideal for applications that require individual or batch labels that contain variable data bits or fields that change frequently and cannot be serviced by an outside printing agency. In such cases, thermal printers promote efficient and flexible label production with virtually no label waste, enabling users to print only what they need when they need it.

Alternating label widths and/or length materials are frequently being used
Thermal printers are ideal for labeling applications with varying label widths and/or lengths because they adapt to varying size labels easily and promote label production without waste. Comparable available print technologies, such as laser or dot matrix, cannot make such claims because of the waste factor and the limited availability of label materials and/or sizes in sheet or pin feed format.

Graphics printing and/or unlimited adjustable (scalable) text font sizes are desired
Thermal printers not only promote user-flexibility to print individual or batch labels on alternating size media. It is the only print technology whose software permits you to incorporate and print virtually any custom graphic or international symbol, be it your corporate logo or other related universal graphic icons such as Fragile, UL, or Flammable into the label design. Text fonts are also scalable meaning that they can be adjusted to any point size requirement. Bitmap fonts, by comparison, are only adjustable to a limited number of point sizes – e.g. 8, 10, 12, 14, 16 or 18 point sizes. A printer’s a capacity to operate such text fonts or to download graphic formats is dependent on the amount of memory that the printer has to adequately store and process such information. The more memory a printer has, the more complex fonts operations it can perform and process more quickly and efficiently.

High density bar codes are needed
Thermal printing is ideal where high density (crisp, high definition / contrast) bar codes are required. Thermal print bar codes also have one of the highest scanner read rates compared to comparable print technologies.

Clean, quiet, compact printer operation with low maintenance and operating cost is preferred
Thermal printers are highly compact promoting clean, quiet operation compared to comparable print technologies, such as dot matrix or ink jet printing, for example. Thermal printers come in two basic varieties – tabletop and desktop. Tabletop thermal printers are typically bigger than desktop thermal printers in size primarily because of their ability to hold a full 8" roll of media compared to the 3-5" roll capacity of a standard desktop printer. (Larger roll capacity enables users to print longer without frequent interruptions to change or replace media which can effect one’s overall productivity, dependent on the number of printed labels required).

From a space consumption perspective, tabletop printers typically take-up the surface area of a typical office laser printer, whereas a desktop printer utilizes about the surface area of a typical office phone or standard mouse pad. This surface area or space consumption comparison is typically referred to as the printer’s footprint within the bar code industry.

From a cost perspective, thermal printers tend to have a higher initial cost but a lower long-term maintenance and operating cost compared to standard office or document print technologies. This is due, in part, because thermal printers are considered a specialized print technology, accessible through a limited number of channels compared to that of popular office printing equipment which is readily available at any retail store. In the long-term, the total cost of ownership of a thermal printer is lower due to (1) lower maintenance costs; (2) efficient label production with the decreased occurrence of label waste; and (3) steadily decreasing prices of ribbon and thermal based papers. Lower long-term maintenance costs quickly offset one’s initial investment cost enabling a rapid return on investment to be realized, especially when coupled with the increased efficiencies of bar coding automation on the whole.

6. How to Specify the Right Thermal Printer

The selection of the most suitable thermal printer is dependent on a number of variables that collectively dictate a printer’s overall sticker price. In general terms, the more printer features and options one chooses– the higher the printer’s sticker price.

Having completed the exercise of outlining one’s application requirements and budget criteria, you can now proceed to analyze which thermal printer model is best suited for your application based on the following printer performance variables:

Required Image Longevity & Stability
The environmental conditions that both the printer and label will be exposed to are important criteria to consider in choosing the right thermal printer for the job. Some Zebra printers, for example, are specifically designed for harsh industrial environments to endure hardship versus others which are better equipped for moderate to light industrial or office use, as dictated by the application. (The next section entitled Zebra/Eltron printers at a Glance will highlight the differences in industrial grades between the various Zebra printer models).

Direct Thermal versus Thermal Transfer
In terms of label longevity and stability, thermal transfer is the only alternative if crisp, long-lasting images are required to last for a number of years - e.g 1 or more years. Direct thermal printers, in comparison, are ideal for short-term applications where the label is only required to last for a limited amount of time – e.g. 1 week to 1 year. Bear in mind that direct thermal is not as durable as thermal transfer, especially when exposed to direct sunlight or other harsh chemicals. Direct thermal paper varieties are also somewhat more limited than those available for thermal transfer printers.

Volume of Label Output Required per Day
Another important factor to consider in the printer selection process is the daily required label output or volume. Some Zebra printers are designed to operate continuously, during peak print cycles or non-stop for 24 hour cycles, while others are better suited for lower volume, intermittent printing. The volume of labels coupled with the application environment frequently determine which thermal printer is best suited to accommodate or perform to that capacity.

DPI Resolution
Most Zebra printer models offer a standard of 203dpi resolution. Certain Zebra models, however, also offer higher print resolution options like that of 152, 300 or even 600 dpi. Depending on your application, higher resolutions or dots per inch may be required to facilitate the printing of text and bar codes on small or miniaturized labels, such as those commonly used in the electronics or pharmaceutical industries for component or specimen labeling. Higher print resolutions enable more detailed labeling (often highly miniaturized and compact) to be accomplished without impairing print quality and scanner readability.

Print Speed
Print speed is yet another factor that differentiates one Zebra printer from another. Some printer models can outperform others, printing at a maximum print speed of up to 12ips (inches per second). Others are more limited printing at maximum print speeds of 2ips. Still others print within designated ranges between 2 and 6ips. Depending on the application and the daily volume of labels required, print speeds are important issues to consider to ensure that the specified daily volume requirement is met and that the printer can produce labels as quickly as required.

Note: A printer's true print speed, irrespective of the print speed that is published on the printer specification sheet, is dependent upon two criteria: (1) printing time and (2) label formatting time. Throughput is the combined equivalent of printing time plus formatting time. It denotes the time span from receipt of the print command to the completion of the printing process. Formatting time is the time required to convert the program to an image of the label. Depending on the complexity of the label format and the printer's ability to process this information in an efficient manner, label formatting time can sometimes cause significant print delays, effecting a printer's overall print speed capability. Such delays can be annoying as well as costly if they occur in a production environment where time and on-demand print capability are of the essence.

Zebra has combated the issue of print speed format delays by engineering many of its printers with sophisticated electronics, e.g. dual processors (on our Xi Series printers) which enable the printer to format a label while printing. In addition, our ZPLII (Zebra Programming Language) optimizes print speed and first label output through its ability to begin printing the label image even before the label format processing is complete.

Print Width
Print width, similar to print speed, differs from one Zebra printer to another. Many of Zebra's printer models are designed to print 4" wide labels. Still others print can print 3", 5" or 6.6" labels. The widest available print width on a Zebra printer is 8.5". Depending on the application and your required label width (e.g. the widest label you will need to print), print width becomes yet another criteria that one must consider in choosing the right printer for the job.

Note: Label images can frequently be rotated to print in landscape or portrait mode through the printer programming code or software, e.g. ZPLII or BAR-ONE. Consider the following example:

A 6" wide printer can print a 4" x 6" format in one of two ways: (1) vertically in portrait mode or (2) horizontally in landscape mode, as demonstrated by the visual examples below. By simply rotating an image using the software or programming code, a 6" wide printer can effectively print a 6" wide format. Thus, expanding its application uses even further.

ex. 4W x 6L

ex. 6W x 4L

In the 4"W x 6"L format depicted above, the bar code is shown in a "ladder" style format. The 6"W x 4"L bar code format is shown in a "picket fence" style. Zebra's E3 (Element, Energy, Equalizer) printhead technology, inherent within all Zebra Xi Series printers, ensures that the correct amount of heat is delivered to each part of a printhead at all print speeds in order to optimize the quality of the barcodes that are produced. E3 is particularly helpful when printing ladder style bar codes, which are the more difficult of the two bar code formats to produce. It also prolongs printhead life by activating only those heating elements that need to be activated at a given point in time, translating to less wear.

Printer Options
One of the last factors to consider when purchasing a thermal printer are the printer options that are required and/or desired for the application or user operating the printer. Depending on the printer, certain features are offered standard, while others are offered as options at additional cost. Depending on the printer model, these options include:

·         Several different print modes (e.g. cutter, peel, tear, and internal rewind of backing alone or label with backing, depending on the printer model and options selected)

·         Flexible communication options (e.g. parallel, serial, twinax, coax, ethernet)

·         Numerous flexible memory options (e.g. Flash, PCMCIA, increased DRAM) and/or font options (scalable versus bitmap, Non-roman (or international character symbols) versus TrueType).

Many Zebra printers offer such options as standard features which naturally has a bearing on printer list price. As a general rule of thumb, the fancier the options – the higher the printer list price. Any of these options, incorporated either independently or in conjunction with one another into a printer can help it to perform and adapt more readily, not only, to the constraints of your application, but more importantly, to the user’s preferred mode of operation and / or work habits. The peel mode option, for example, when installed on a Zebra printer can facilitate quicker label application for a user. In peel mode, the printer will actually separate the label from its liner backing making it easier for the user to grab and simply adhere the label to the item versus having to remove the label from its liner manually. Such time saving options can greatly facilitate label output and in some cases even improve worker morale.

More importantly, however, when a proper balance is reached between printer performance capability and application criteria and/or budget, the printer becomes a more natural extension of the worker or operator, facilitating their ability to do their job more efficiently. Thus, increasing their overall productivity which translates to increased profits and money savings to the organization as a whole.

7. Zebra / Eltron Printers at a Glance

Zebra designs and manufactures complete labeling solutions that integrate application and print systems expertise with software and specialty supplies. Zebra offers the broadest line of bar code printers available on the market today.

Zebra’s recent merger with Eltron serves to round out our product assortment so as to capitalize on the unique brand strengths of both companies. Zebra brand’s dominance in the manufacture of reliable, high performance tabletop printers coupled with Eltron brand’s superiority in the desktop and card printer arena, ensure that our customer’s specific application requirements are met.

The comprehensive Zebra/Eltron product line includes fully compatible, industrial thermal transfer, direct thermal and card printers. The units range from low-cost, general purpose printers to highly specialized models tailored for custom applications and system requirements.

Zebra Brand Printer Products include:

Zebra’s Xi Series tabletop printers (90XiIII, 96XiIII, 140XiIII, 170XiIII, 220XiIII ) deliver unmatched performance and Zebra reliability for the most demanding, mission-critical applications.

The S Series (105Se , 160S ) tabletop printers combine Zebra reliability and functionality with a choice of convenient options, in a cost-effective, all-metal package.

The Z Series (Z4000, Z6000) printers incorporate a variety of technology enhancements and Zebra Reliability in an easy-to-use printing solution that delivers performance and flexibility.

The Stripe Series (S400, S600) printers deliver Zebra reliability and represent Zebra's lowest priced, full size printer.

The Stripe Series (DA402, T402) desktop printers deliver compact simplicity and Zebra reliability in basic, low-volume label printers.

Zebra Portable Line (PA400, PT400) printers are designed for mobile workers who seek a print solution that is rugged, flexible and adaptable to move with them.

Eltron Brand Printer Products include:

Eltron's Strata (2684) is for 8" wide applications which have space and budget constraints and offers a cleverly contoured, low-profile, metal wide-web printer.

TLP 2746 delivers the lowest priced, full-sized, metal printer solution and is perfect for medium duty cycle applications on a low budget.

LP/TLP 2700/3700 Series is the proven, reliable, on-demand flagship desktop printer for distributed, dedicated applications, which are budget sensitive.

Eltron's stylish Orion (2443) provides an extremely easy-to-use desktop printer utilizing OpenACCESS technology for low volume, direct thermal applications.

Eltron's Companion Plus (2231) printer is the perfect mate to retail operations with a sleek, compact, durable receipt printer at the industry's lowest price.

In addition to printers, Zebra provides an easy-to-use, Windows-based software package, entitled BAR-ONE, which contains many powerful features that allow you to design and create your own custom labels with any combination of text, bar code or graphic for virtually any specification requirement. And when you use BAR-ONE including JetForm Central, you can easily output your labels from 15 different platforms, including Windows, HP UNIX, IBM AS/400 and IBM OS/2 to name a few, without modifying your existing application.

Zebra's line of specialty ribbons and media supplies encompass a wide variety of paper and synthetic materials, from tear-proof Tyvek to UL Recognized polyester and scratch resistant Z-Ultimate facestocks, that complete the product offering. Zebra supplies, when combined with the superb printing capabilities of the Zebra printers, produce consistently durable labels, tags and tickets for all your marking and tracking needs. And if you have a labeling application that cannot be solved using existing Zebra supplies products, Zebra's research specialists can design a customized labeling solution for you, utilizing special die-cuts, adhesives and facestocks. Zebra's label presses also have the capability to preprint labels, tags or ticket media stocks in up to four different colors, in perforated or fanfold variety.

For more detailed information , specification sheets are available for download on this website which highlight the specific features, options and performance capabilities of the entire Zebra Printer Product Line encompassing our printers, software and supplies.

Regardless of your application or budget criteria, Zebra / Eltron printer products, software and supplies are guaranteed to deliver quality performance at a price point suitable to your needs.

8. Optimizing your Print Application

Choosing the Right Materials & Print Accessories
There are a number of variables involved in printing labels with thermal and thermal transfer printers. With careful consideration of your application, you can choose the right materials to work with your printer to guarantee optimal printer performance and consistent print quality.

The key to specifying the correct media, similar to the correct printer, involves a solid understanding of the application. Zebra recommends analyzing the following label supplies related issues in conjunction with your thermal printer selection:

Desired Print Technology
Dependent on whether direct thermal or thermal transfer print technology is chosen to satisfy your application requirement, the selection and types of label material utilized will vary accordingly. For optimum printer performance and the extended life of your printhead mechanism and/or label, it is important to select the right media and ribbon (in the case of thermal transfer printing) to perform with your printer and within the constraints of your application. Choosing the wrong media can result in poor print quality, printer malfunction and/or frequent printhead replacement. Your local reseller and/or Zebra Supplies Specialist can assist you in choosing the right thermal materials to operate with your Zebra printer.

Media Type
Thermal printers are designed to operate with a variety of media types, including pressure sensitive, die-cut, butt cut, perforated, notched, hole-punched, continuous, tag or ticket stock labels. The diagrams below highlight some of the most popular label varieties used:

The type of media sensors the printer has dictates its ability to operate with certain media types. Unless the media is continuous, die cuts, black marks, or notches help the printer determine the top of the label. Zebra printers come equipped with a variety of media sensors that enable the printer to gauge vertical label length during the media calibration process.

Calibration is a process that a printer performs in order to gauge the length of the label material loaded within it. Sensors within the printer’s media compartment – commonly located around the printhead - detect either the white spaces (inter-label gaps) or black marks and/or notches on the reverse side of the label stock that represent a label’s actual face size (length). Printer calibration ensures that one’s data is aligned and prints correctly on the label stock.

Zebra printers can be configured to contain any one of the below sensor varieties:

Transmissive Media Sensor – is used to gauge label length for media with visible interlabel gaps, notches or pre-punched holes. Light from the sensor passes through the gaps in the label materials semi-transparent backing enabling the printer to measure label length during calibration.

Reflective Media Sensor –similarly, a reflective sensor emits light which is reflected back to the sensor when it reaches a black mark appearing on the reverse side of the label stock. Such specialized media is commonly referred to as black mark media.

Dual Media Sensors – two sensors within the printer (one reflective and one transmissive) that have the ability to detect both interlabel gap and black mark media, irrespectively. Zebra Xi Series printers come equipped with dual media sensors.

Multi-functional Sensor – refers to a single sensor within the printer that has the ability to detect both interlabel gap and black mark media, irrespectively. Zebra Z-Series printers come equipped with multi-functional sensors.

Application Surface
Application surface is another important factor to consider when selecting the right media to operate within the constraints of your application. Application surface refers to the type of surface upon which the label will be applied. Surface features can be flat, smooth, curved, rough, rigid, flexible, clean or contaminated (dust, oil, powder, etc). Certain media types may be better suited to deal with certain application surface criteria than others.

Adhesive Type
Adhesive type refers to the label’s level or degree of adhesiveness. Generally speaking, there are two types of adhesives, acrylic and rubberized. A rubberized adhesive label is a pressure-sensitive adhesive based on natural or synthetic rubber. Rubber based adhesives offer good general purpose performance and may be used on a wide variety of surfaces and temperature ranges. They can be used on most packaging materials, including plastic, glass and metal. Rubber based adhesives provide excellent adhesion to corrugated materials. Most importantly, rubber based adhesives have a high initial tack. Meaning they stick immediately to a surface which makes them particularly useful on curved or irregularly shaped surfaces.

An acrylic adhesive label is pressure-sensitive adhesive based on high strength, acrylic polymers. Unlike rubber based adhesives, acrylics require a short period of time to set (a minimum of 24 hours). Once they are set, they provide superior permanence and durability. Acrylics are extremely strong and resistant to environmental conditions which make them suitable for heavy duty applications.

In addition, some label media varieties come equipped with a permanent adhesive while others are removable enabling them to be lifted off and re-adhered again elsewhere. Still others are recyclable, freezer-grade, patterned or tamper evident:

Freezer-grade labels are designed to be applied in an extreme cold (-20F) environment. Freezer-grade materials can be applied at much lower temperatures than other adhesives.

Patterned labels are labels that have adhesive on a portion of the label with another portion of that same label having no adhesive. Jewelry tag labels are a perfect example of this label type. The two ends of the jewelry tag have a permanent adhesive while the middle part has no adhesive so as not to stick to the jewelry item itself.

Tamper evident labels have acrylic adhesive whereby a pigmented adhesive is used to leave the word "VOID" behind on the product if the label is removed. Such labels are ideal for labeling physical assets where security is essential.

Application Temperature
Application temperature refers to the minimum or maximum temperature present at the time the label is to be applied to the item or product in question. Application temperature is important in that some adhesive materials are better suited to deal with extremes in heat and / or cold. A label that is not suitable to the application temperature it is subjected to may not stick properly. Thus, defeating the whole purpose of bar coding as a means of automating certain functions or processes.

Service Temperature
Service temperature differs from application temperature in that it specifically refers to the temperature range that the label must withstand throughout its useful life. Zebra’s Supplies Selector Guide is a helpful reference tool that can be used in order to gauge the application and service temperatures for our various media types.

Exposure
Exposure refers to the type of environmental conditions and/or stresses that the label or tag must withstand. Common stresses found in labeling applications to take into consideration when choosing a media type include moisture/humidity, chemicals, abrasion, sunlight, heat, cold, blood etc. Any such factor when coupled with the wrong media type that is not designed to withstand such stress can result in poor print quality, printer jams or fading.

Method of Reading the Label
The method of reading a label can differ depending on the application. The two most common methods of reading a bar code label are through the use of (1) scanners that interpret information when linked to an external computer database, or (2) human readable symbologies that are visible and can be read easily with the human eye. Human readable information runs the risk of being misread by a worker which can sometimes cause errors. Infrared scanners, though a reliable form of data capture and transmission, operate best when used within certain distance ranges. When purchasing a scanning product, it is important to make sure that the scanner can perform within the distance range you need it to. Scanner manufacturer’s do specify the distance read capability of their product on their specification sheets.

Method of Application
Method of application refers to the manner in which the label is to be applied. Label application can be accomplished, primarily, in one of two ways – e.g. by hand or by utilizing a label applicator system. Hand application is the more economical approach, yet it is not as expedient compared to that of an applicator system. Applicator systems are frequently accomplished utilizing pneumatic cylinders. A conveyor or pneumatic cylinder system can align and position a product toward a labeling station where a pneumatically driven applicator arm then adheres a peeled label to the side of the product. Such applicator systems can be either simple or complex in nature which naturally require a larger budget to accomplish.

Re-Cyclability Factor
For some applications, recyclable label material may be preferred. Linerless label stock is a perfect example of how an ecological concern for the environment resulted in the production of more environmentally friendly label materials. Linerless label media, as its name suggests, utilizes no liner backing. It commonly consists of continuous media with no perforations. Its top surface can be printed on, whereby its reverse side contains a light adhesive. Thus, foregoing the need for the liner altogether. Linerless label materials are particularly popular in many European countries. In light of this trend, Zebra/Eltron offers a number of printer models that have this specific print capability.

Budget
Whether choosing a printer or labeling supplies, one’s budget for spending plays a critical part in the product selection process. It is essential not to overlook the cost of labeling supplies in reviewing one’s application. In all actuality, the label itself should always be your first area of concern. From its size, content, industry compliance and material type, to the selection of the appropriate printer to print that label with - one’s entire labeling application revolves around the label. One’s budget concessions, therefore, must effectively take both areas of label supplies and printer selection into account.

9. The Future of Bar Coding / Why Zebra

Thermal print technology continues to satisfy an ever-growing number of labeling applications. Over two decades of product development have resulted in the broadest range of barcode printers capable of fulfilling a variety of tasks to meet the requirements of barcode system engineers and end-users throughout all sectors of industry. Some of the biggest, most profitable, best-known companies in the world use Zebra. Our product reliability, which began as our foundation, is now our reputation. Add to that the addition of new technologies such as RFID (Radio Frequency Identification) and Ethernet connectivity to achieve a wireless print solution and exciting new print capabilities are born.

As for the future of bar coding and whether it has achieved its full potential?

Not the way we see it! The possibilities of bar coding are practically endless. With a commitment to research and development, Zebra will leave no stone unturned in our quest to find better ways to make bar coding work for you and to build better products to meet your specialized needs. We will never be satisfied with status quo so as to continue to provide our customers with the highest quality bar code products and services available.