1. Look at the paint's aqueous solution: After a period of storage of colorful paint, the patterned particles will sink, there will be a layer of protective glue solution. This layer of protective glue solution, generally about the total amount of colorful paint. Where the quality of good multi-color paint, the protective glue water solution was colorless or yellowish, and more clear; and poor quality of multi-color paint, the protective glue water solution or greatly more than the total amount of multi-color paint, or in a muddy state, obviously the same color as the decorative grains, the main reason is not the stability of the multi-color coating is poor, or storage period has passed, not suitable for use. 2. Look at the floating things in the paint: where good quality multi-colored paint, in the Protection Glue Water Solution Surface, usually is not floating things, if there are also very few colored particles floating things, is still normal; but if the floating things in large quantities, color particles covered with protective glue solution of the surface, and even have a certain thickness, is not normal, indicating that the quality of this multi-color coating. 3. Look at the particle size of the paint: take a transparent glass, fill it with half a cup of water, then take a small amount of paint into the glass of water stir. Where good quality multicoloured paint, the water in the cup is still clear to see the bottom, the particles are relatively independent in the clear water, there are no anions and cations bonded together, the size of the particles is also very uniform; and the poor quality multicoloured paint, the water in the glass immediately becomes cloudy and polarized in particle size, with a few large particles appearing as lumps and a large number of small, fluffy particles. 4, look at the sale price of paint: where good quality multi-color paint, are produced by regular manufacturers according to the formula, the price is moderate; and poor quality multi-color paint, some manufacturers in the production of jerry-built materials, some even personal counterfeit production, the cost is low, the sale price is much cheaper than the good quality multicolor coating. So consumers in the purchase of paint when do not covet cheap and buy poor quality paint.