After some period of using, you may find that your makeup brush ferrule becomes rusty which is actually a kind of metal oxidation. It is really horrible for a beauty tool.
Although makeup brush ferrule is made of metal (aluminum or copper) with electroplated coating, qualified brushes should never have such problem. Before being assembled to makeup handle, the ferrules need to pass the salt spray test (or salt fog test).
The salt spray test is one of the most widespread and standardized corrosion test method, used to check corrosion resistance of materials and surface coatings. Usually, the materials to be tested are metallic and finished with a surface coating which is intended to provide a degree of corrosion protection to the underlying metal.
Salt spray testing is conducted in a closed testing chamber, it is in nature an accelerated corrosion test that produces a corrosive attack to coated samples in order to evaluate the suitability of the coating for use as a protective finish. A salt water solution is applied to a sample via a spray nozzle. This dense salt water fog is used to imitate a corrosive experiment. Test duration depends on the corrosion resistance of the coating; generally, the more corrosion resistant the coating is, the longer the period of testing before the appearance of corrosion or rust.
If your makeup brush ferrules are rusty, it means that the makeup brush factory does not follow standard process, and omit the salt spray test step, maybe to save money, maybe they have no such testing machine. That is why they can offer lower price than other makeup brush manufacturers.
Kingyin has strict incoming inspection process on ferrules. Ferrules are placed on the salt spray test machine and subjected to calibrated amounts of salt for 24 hours. Only qualified ferrules can pass to our production lines.
To OEM makeup brushes and custom makeup brushes, it is better to work with professional makeup brush manufacturers with standard production and QC process, which will greatly support your brand development and business increase.
