Q: What sort of printers can be used to print barcodes?
A: There are four basic types of barcode printing technology: Dot Matrix, Inkjet, Laser, and Thermal (Direct Thermal and Thermal Transfer). Your choice of barcoding printing technology depends upon your application and the materials you will use to create labels.
Different types of barcode label and ribbon materials (i.e. wax, resin, paper, polypropylene, serve different purposes. Whether you need a permanent label designed to weather the elements or a shipping label meant to last three days.
Dot Matrix
Dot matrix print technology is a longstanding method of producing barcodes on-site. The barcode image is produced by hundreds of dots printed in a matrix to make the series of lines and spaces commonly referred to as a barcode.
Advantages:
- Printers are easily accessible and a less expensive option of printing
- Various surfaces can be used to print on
- Multi-pass ribbons can reduce costs for ribbons and label materials
Limitations:
- Barcodes are low to medium density and may not match up to a users standard
- Reusable ribbons can produce illegible barcodes resulting in lower read rates.
- Ink saturation can result in bleeding on the paper resulting in image distortion
- Though many types of material can be printed on, often these labels are not durable, nor can they be water or chemical resistant.
- Printing of single labels results in a great loss of media and is inefficient
- No graphics capability
- Speed is suffered when trying to produce best ink coverage for optimal readability
Ink Jet:
Ink Jet printing is usually used in high production settings where production of barcodes and human readable fonts need to be reproduced at high rates of speed.
Advantages:
- Direct ink jet printing requires only one step to finish the carton or readable material, where other forms may require adhesion of a label to the finished product
- A favourite on high-speed production lines due to its ability to mark "on the fly"
Limitations:
- System installation is very costly as this method is designed for high-volume barcode printing - not for individual or batch printing
- Requires constant supervision to prevent inkjet clogging and maintain proper print quality
- Material use is restricted due to possible bleeding on certain materials
- Printing on dark backgrounds, such as corrugated cardboard, result in hard to read barcodes. Scanning devices must be chosen carefully to ensure proper readability.
Laser:
A laser printer works much like a photo copier. Charging particles of the paper that then attract ions from the ink. These two particles are then bonded together by the heat and pressure of the drum.
Advantages:
- Print high-quality text and graphics on paper documents and can double as a document printer when not being used to print barcodes.
- Density and resolution are relatively high, allowing the production of scannable barcodes at any wavelength when read with an infrared scanner
Limitations:
- Not well suited for industrial environments
- Wasteful in small operations
- Label adhesives must be strong enough to withstand the heat and pressure of the fuser
- Limited durability - cannot produce water resistant nor chemical resistant labels. Toner costs are generally huge with laser printers as they require five times more toner than normal text
Thermal:
Thermal printing includes Direct Thermal and Thermal Transfer, as explained below.
Direct Thermal:
Direct thermal printing is an older technology designed for use with copier and fax machines that utilizes chemically coated paper. It has since been transformed into a highly successful technology for barcoding. The direct thermal print head consists of a long, linear array of tiny resistive heating elements (roughly 100-300/in.) that are arranged perpendicular to the flow of the paper. Each print head element locally heats an area directly below it on the paper. The image is produced by rows of dots caused by chemical reactions that are formed as the media passes beneath the active edge of the print head.
Advantages:
- Produces sharp print quality with great scan-ability
- Ideal for applications with a short-shelf life such as shipping labels and receipts
- Simple to operate and inexpensive to maintain - no ink, toner or ribbon to monitor or replace
- Batch or single label printing is available with minimal waste. Generally Thermal printers are built more durably than dot matrix or laser printers
Limitations:
- Sensitive to environmental conditions such as heat and light
- Paper remains chemically coated after printing, sometimes requiring a coating adhered to the paper to protect from UV light exposure, chemicals and abrasions
Thermal Transfer:
Thermal Transfer printers use the same basic technology as direct thermal printers, but replace chemically coated paper with a non-sensitized face stock and a special, inked ribbon. A durable, polyester ribbon film coated with dry thermal transfer ink is placed between the thermal print head and label. The thermal print head transfers 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:
- Crisp, high-definition text, graphics, and barcodes for maximum readability and scannability
- Produces long life standability
- Produce batch or single print labels with minimum waste
- Long-term maintenance is low compared to dot-matrix, inkjet, and laser
- Print on a high variety of media stock
- High durability
Limitations:
- Supply costs slightly higher than Direct Thermal as Thermal transfer requires ribbon replacement, though their print head lasts longer
- Ribbon can be wasteful if little is printed from it
- Poor candidate for recycling
- Ribbon and Media MUST be compatible.