Thermal paper: what is it?
What is Thermal Paper?
Thermal Paper is special fine paper that is coated with a chemical that changes color when exposed to heat. Thermal paper is used in Point of Sale printers such as credit card terminals, cash registers, adding machines and similar devices because it does not require a POS ink ribbon or cartridge to display information.
A Brief History
The first direct thermal print head was developed by Texas Instruments in 1965 and added to a computer terminal in 1969 (in the Silent 700). Later to be followed by Hewlett Packard in the 70's.
Thermal printers typically used thermal paper developed by NCR Corporation using dye chemistry or the more expensive version by 3M using metallic salts. In the 1980's and early 1990's the rise of laser printing and inkjet printers started to take the place of thermal paper in industrial applications such as the facsimile market. Direct thermal printing soon found a home and increased use again in sales receipt rolls due to the print speed that it was able to attain.
How Do I Know If My Paper Roll is Thermal?
You can do a simple test to figure out whether your paper rolls are Thermal paper or Bond paper. Take about 6 inches of the paper roll you want to test. Try to draw a line by pressing your fingernail (or scratching) on one side of the roll. Your paper is Thermal if you were able to draw a line.
Repeat the test on the other side of the paper roll. You will need to do the test on both sides, because the Thermal coating could be applied to either side of the roll.
You may have heard the terms "Coated Side Out (CSO)" and "Coated Side IN (CSI)" for Thermal paper rolls. If you were able to draw a line with your fingernail on the outside (top side) of the roll, then your Thermal paper is CSO. If you were able to draw the line with your fingernail inside (bottom side) of the roll, your Thermal paper is CSI.
If you cannot make a mark with your fingernail on either side, then it is Bond paper. If your paper roll has multiple layers (2-ply or 3-ply), it is Carbonless paper. You will need a Dot Matrix / Impact Printer and Printer Ribbons for printing on these types of paper.
