The first is chromaticity. The whiter the paper, the better. On the contrary, paper with good quality is darker in color, because it is less irritating to the eyes.
The second is the uniformity of texture distribution. Pick up the paper and illuminate it with light to see the texture distribution of the paper. The more evenly distributed, the better the paper.
The third is thickness. Ordinary office paper (A4/A3) is mostly 70g and 80g. Feel the thickness with your hands. At present, 70 grams of paper can reach 67 grams, and 80 grams can reach 78 grams.
Fourth, you can look at paper ash. Burn the paper with fire, and look at the paper ash after it is completely burned. The whiter the paper ash, the better the paper, and vice versa.
Fifth, there are secondary conditions such as cutting paper to cut corners, paper ash and packaging, so I won't talk about them one by one.