Both times you were holding thermal paper, and both times that particular business was supplied with a high-quality product.
As a business, you're going to be going through rolls upon rolls of this stuff, it's going to come in the form of receipts and anything else purchase-related (that produces a paper) you can think of. This paper is a very unique type indeed, it has a coat of chemicals on it that will change the paper color when it's been heated. You might have noticed something like this if you've ever bought a burger at a fast food place; have you ever got the receipt on the box of your sandwich and it looked a little “burnt”?
That's the thermal paper working it's magic, as when it's placed near a source of heat it begins to change color and give off a burnt look (without actually being burnt, of course). This paper was initially introduced to the market in the 1990's, and ever since then it's just been expanding its horizons. These thermal papers have these coatings for a reason, it wouldn't be practical to coat the paper for no particular reason, now would it? The reasons can come in abundance depending on who you're talking to, but the most common reasons would be:
- Make sure that fading is reduced when UV light hits the paper (or oils/greases/fats, hence why fast food restaurants use them so much)
- Improve upon the print head wear
- Completely eliminate residue when the paper is printed on
- Allow for the inks to be transferred at a more successful rate