△ Cheng's works (in kind)
First, look at the net pattern and touch the net pattern: the hand-made net pattern is the trace caused by the small bamboo curtain of papermaking, which is very clear. Hand-made propaganda is rough on both sides, not very smooth. See if there are any pine needle patterns, which are traces of dry paper brushes. Then look at the first and last sheets of a knife to see if the uniformity of these two sheets is the same. If so, it is not pure artificial propaganda, but mechanical propaganda. Because only 60 pieces of handmade rice paper can be fished in the pond, its uniformity will not be the same.
△ Cheng's works (in kind)
2. Pick up the paper and look at it in the light: See if there is cloud-like paper on the rice paper, which is sandalwood fiber, and you can also find scribbled ribs (each paper can always be 8 to 10 2-3 mm long), but this method can only identify whether it is pure sandalwood paper or grass paper, and it cannot be used as the key to identify whether it is handmade paper.
△ Cheng's works (in kind)
Third, look at the four sides of the whole knife paper: if it is neat, it is not pure hand-made rice paper. Most hand-made rice paper is irregular because it is cut by hand, but hand-made rice paper can also be cut by machine.
△ Cheng's works (in kind)
Fourth, test the change of ink with a pen: trace several shallow and thick ink marks in the same place on the paper, and observe the ink absorption change of rice paper. If it is handmade rice paper, it will clearly show the levels between ink marks. However, the mechanism of Xuan paper and painting paper at the alternation of pen marks is vague, and the ink absorption effect is not rich, so it is impossible to distinguish the ink color change.
△ Cheng's works (in kind)
Verb (abbreviation of verb) tearing method: When manual rice paper is torn longitudinally, it will show a very obvious double layer with a width of 2-3 cm, while machine-made paper is often single layer. This acidic structure caused by chemical bleaching agent corrosion has weak tensile strength.
△ Cheng's works (in kind)
6. Combustion method: This is the simplest identification method. Because the traditional manual propaganda is weakly alkaline and acid-free, if the paper is grayish white after burning, it is pure manual propaganda. If the paper ash is gray, it is acid paper, which is undoubtedly machine-made rice paper. This is because the carbonization of carbon and sulfuric acid in acid paper promotes the formation of carbide, which leads to the darkening of ash.
△ Cheng's works (in kind)
7. vinegar bubble: soak a small piece of paper in vinegar. If there are tiny bubbles, it is mostly hand-made rice paper. This is because acid-free paper contains alkaline fillers (such as calcium carbonate). Acetic acid in vinegar will react with calcium carbonate and release carbon dioxide. The bubbles we see are carbon dioxide.