Bar code label printers are generally the most common dot matrix, laser, and ink jet and thermal printers. Dot matrix printers are one of the oldest printers used for printing bar codes. In these printers, the lines are built dot-by-dot as a solenoid-driven needle strikes an ink ribbon, transferring the ink to the paper. These printers are inexpensive, can print any form and are easily accessible. However, the quality dot matrix printer is unacceptable today. Ink jet printers are one of the most commonly used printers, especially for high-speed applications. They can also be used to print directly onto a carton where a label has already been affixed.
However, they are suitable for only high-speed printing and may not be very cost-effective for small-scale bar code printing operations. Ink jet clogging, limited barcode resolution, “bleeding” ink, and poor contrasts are some of the disadvantages. Laser printers are quite good as far as the quality of the print is concerned. They have very good resolutions and can scan quite well. However, they cannot effectively print smaller labels. The adhesive on the labels has to be good enough to take the heat and pressure from the printer as most label adhesive tend to melt. Thermal printers for bar coding are of two types: direct printing and thermal transfer.
Bar code printers have to be analyzed on the basis of: quality of the print, readability, initial installation cost, speed, long-term maintenance cost, materials waste. Each of these printers has different results. Thermal label printers score well on all aspects except for material waste. They are most suitable for applications that have variable data fields, point-of application systems, varying label sizes, graphical and scalable text fonts, and high-definition bar codes. They are also compact, quiet, and have lower operating costs.
Today, there are special bar code label printers available with various options like different print modes, label cutter, liner take-up, peel, rewind, tear, real-time clock (for printing time and expiration dates); alerts for maintenance; portability, compatibility with parallel; serial, USB, wired or wireless Ethernet, twinax or coax cables; memory for storing frequently used data; font options like styles and colors; multi-lingual options; sensors and many more. These printers are also compatible with different sizes and materials of labels, including water-resistant, fabric or acrylic.