Sunscreen Test
This is another way of testing. It uses a special ultraviolet light instead of the sun, and some paint that glows when ultraviolet light shines on it. The more ultraviolet, the brighter it shines.
More Testing
Every time the sun protection material is made, a bit of it must be tested to make sure it has turned out right. This is called quality control and is used to make sure every batch is the same.
Find out more about quality control