Bar Code Printing

Almost any type of printing method can produce bar codes. The best method will depend on the application. Speed, flexibility, volume, data density and turnaround time must all be considered.

Impact Printing

A physical contact with the label is made.

Dot Matrix

Dot matrix involves the firing of pins against a ribbon and then onto a paper, producing a small dot of ink per each pin on the paper surface.

Advantages:

• Low cost of label materials and ribbons to generate high-quality bar codes.
• Very reliable in industrial environments.
• Ability to produce multi-across labels.
• High print speed rates.

Disadvantages:

• Limited bar code print density.
• Noisier than other print technologies.

Flexographic or Offset Printing

This process involves a large label printing press in conjuction with rubber, cyrel or metal printing plates. The primary application for offset/flexographic bar code labels involves long run labels where variables do not change.

Advantages:

• Low cost per label.
• Fairly high-density bar codes can be produced.

Disadvantages:

• It is only appropriate for large production quantities of identical labels.
• Does not produce serialized bar codes.

Non-Impact Printing

No physical contact is made with the label.

Thermal Printing

It uses heat from a stationary printhead that contains many small resistive heating elements. These elements create dot patterns that produce the actual image on paper.

There are two types of thermal printing technology - Direct and Transfer.

DIRECT THERMAL printers require a specially-coated paper that when heated will reveal a dark substrate.

Advantages:

• Lower supply cost, do not use ribbons.
• Printer model can be economical.
• Excellent resolution of high-density bar codes.

Disadvantages:

• Higher cost of label materials.
• Papers are sensitive to heat and light.
• Printed image may fade or scratch.

THERMAL TRANSFER printers use heat-activated ribbons that actually transfer the ink to the paper. Once an area of a ribbon has been transferred, it can not be used again. Barcode symbols printed with thermal transfer inks can be scanned with any type of barcode scanner.

Advantages:

• Superb resolution of bar codes, text and graphics.
• Prints on a wide variety of label stock.
• Longer printhead life compared to direct thermal.
• High print speed.
• Accepts label and ribbon combinations for almost any application.

Disadvantages:

• Cost of replacing ribbons.

Laser Printing

A latent image is formed on a rotating cylinder or belt by a laser beam. The toner is attracted to this image and then transferred onto paper. The toner is fused to the paper via heat and sometimes pressure. The carbon toner allows symbols printed with these printers to be scanned with both visible and infrared light source scanners. The dot size is typically from 0.005 to 0.007 inch in diameter. This limits the sizes of barcode that can be printed and also requires careful compensation to make the bars and the spaces close to the same widths.

Advantages:

• High-resolution bar codes and text.
• High-speed printing.

Disadvantages:

• Higher cost for continuous-form models and their maintenance.
• Print image may fade with time.

Ink Jet

Ink jet printing sprays dots of ink onto a surface to build the image.

Advantages:

• Elimination of the label and label application cost.

Disadvantages:

• Unreliable print quality.
• Inability to print high-density bar codes.
• Inconsistent bar code readability.
• The need for specially-configured scanners.