Tempera is one of the oldest paints in existence; some tempera paintings date to the first century. In other words, it's permanent. Don't worry, though; the kind you probably have to wash out of your child's shirt or expensive jacket isn't this kind of tempera. It's tempera poster paint, and it's designed to be temporary and washable. The only way you'd have to worry about washing out real tempera paint, which is usually made with egg yolks, would be if you wandered into the studio of an artist who uses it, and there aren't very many of those.
As with most materials, tempera stains are easier to remove when they are fresh. Because tempera poster paint is designed to be washable, you should be able to remove it with <ahref="http: web.extension.illinois.edu="" stain="" staindetail.cfm?id="74"" target="_blank"> </ahref="http:>laundry detergent, but bleaching may be required in some cases.
Blot away any fresh paint, using an absorbent cloth or a paper towel.
Treat the stain with liquid laundry detergent. Spread the detergent liberally on the fabric, let it sit for an hour, then rinse it off.
Mix a dilute solution of color-safe bleach and soak the fabric. If the garment is made from a colorfast fabric, soak it in a solution of 3 tablespoons of chlorine bleach per gallon of water. Leave the garment in the bleach solution and check it after 15 minutes. If the stain is still there, you won't be able to bleach it out.
If you aren't sure if the garment is colorfast, apply a little bleach to an inside seam or some other inconspicuous place as a test.
Use a commercial color remover according to the instruction on the package. This treatment will probably alter the color of the entire fabric and won't work with synthetic fabrics, such as polyester.
To remove paint stains from wool and other thick, textured fabrics, blot up as much fresh paint as possible, being careful not to spread it, then wait for the rest to dry. Scrape off as much as you can with a spoon, then blot the residue with a paper towel and white vinegar.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.