First of all, the chemical reaction on the test paper may interact with the components of lipstick, thus forming an obvious imprint. If lipstick contains some special chemicals, it may react with some chemicals on the test paper and produce obvious color changes.
Secondly, the material of the test paper and the texture of lipstick may affect the application effect of lipstick on the test paper. If the material of the test paper is not absorbent enough or the texture of lipstick is too dry, lipstick may not form obvious marks on the surface of the test paper.
In addition, the method and strength of daubing may also affect the obvious degree of imprint. If the application method is too rough or too strong, lipstick may not form uniform marks on the surface of the test paper.
The above information is for reference only. It is recommended to read relevant books or consult professionals for more accurate information.