1. Appearance: if paper is very white, that is to say, protective coating and thermal coating of thermal paper is unreasonable with too much fluorescent powder, paper must be better with a little green, paper with low cleanness or it looks uneven, that is to say its coating is uneven. If paper looks with strong reflected light, it is also with too much fluorescent powder with bad quality.

2. Roast: it is easy to roast with lighter, heating on the back of paper, if it shows brown, that is to say its thermal recipe is unreasonable with short retention time, if there are some small stripes or uneven color lump, that is to say its coating is uneven. Thermal paper with good quality should be black green ( with a little green) with even color-lump, its color is faded from center to around.

3. Compared to identify by sun shine: paint thermal paper with  nite writer pen and put it under the sun ( it can speed up reacting), which one turns to black fastest, that is to say it is stored for shorter time.