The best way is weighing, weight is the paper can not do a false hom, but also the most fundamental.
Second, it is to look at the paper carton cardboard surface gloss, as the cowhide belongs to the rough paper, the production process on the surface of the gloss requirements are not high, but the requirements of flat, this can be seen in the core paper, which is also the core paper can only do the middle of the wave and the reason, as it is rough, and then the glue adsorption strength.
Hardness and thickness, this is an important parameter of paper quality, hardness is not necessarily thick, thick also does not necessarily have high hardness.
Feel, this is experience, usually more with cardboard contact, you can acquire a pair of "carton box hand", this can only touch more, more poke, more pinch.