Coating testing is categorized into four types: physical performance, processing performance, resistance, and hygiene indicators.
（1）Physical Performance:Solid content, viscosity, relative density, cleanliness, color, flowability, and particle size of the coating.
（2）Processing Performance:Gloss, adhesion, slipperiness, scratch resistance, extensibility, and impact resistance of the coating film.
（3）Resistance:Acid resistance, sulfur resistance, high-temperature resistance, and corrosion resistance.
（4）Hygiene Indicators:
Apart from physical performance, all other tests must satisfy the following three conditions:
（1）Appropriate Substrate:
（2）Correct Film Thickness:
（3）Complete Curing: When determining if a coating is suitable for a specific type of food, reliance solely on the results of coating tests is insufficient. Instead, practical canning trials should be the determining factor.
