Instructions
Purchase a black light. A black light produces an ultraviolet light that many materials will shine under.
Take the object into a dark room with the black light. To test antiques, it is best to take the object to a room where there is no outside light interfering with the authenticity test.
Test the glass on antiques. Shine the light on antique glass products to find out what type of glass was used in production. Pressed glass will glow yellow under the light while green glass from the Depression era will also glow under a black light.
Use a black light on artwork. The black light is often used to tell if a piece of art is a fake or not. Newer paint will shine under a black light while older paints will not cast off a glow.
Examine paper products from the past. Modern paper products will shine when put under a black light. Antique postcards and photographs will not reflect any light.
Find out if an object is made from cast iron. Many toys from the early twentieth century were made from cast iron. To authenticate these toys, a black light can be used to check for modern paint on the object.