Best Way to Keep Tempera Paint on Plastic

Also, referred to as poster color, tempera paint is a permanent, quick-drying coating, consisting of pigment and a glutinous binding agent, like egg yolk. When Tempera peels from plastic, the culprit is almost always improper surface preparation. Because plastic is nonporous, it is ill-suited for any type of paint adhesion. Plastic surfaces should be abraded with sandpaper to provide a tooth for the tempera to adhere to. Properly conditioned plastic will maintain its tempera finish. However, for extra durability, you may want to apply a paint sealer.

Things You'll Need

  • Dish soap

  • Coarse sponge

  • Rags

  • Towels

  • 220-grit sandpaper

  • Tack cloth

  • Heavy-duty fabric drop cloth

  • Acrylic latex primer

  • 2- to 4-inch latex paintbrush

  • Tempera paint

  • Paint sealer

Step 1

Clean the plastic surface with dish soap using a coarse sponge. Rinse the soap from the plastic with wet rags. Dry the plastic with towels.

Step 2

Stimulate surface adhesion by abrading the plastic with 220-grit sandpaper. Scour the surface until it feels gritty.

Step 3

Wipe down the abraded plastic with a sticky tack cloth.

Step 4

Place a fabric drop cloth beneath the plastic.

Step 5

Coat the abraded plastic with an acrylic latex primer, using a 2- to 4-inch paintbrush, manufactured specifically for use with water-based latex paints. Wait two hours for the primed plastic to dry.

Step 6

Wash the brush with water.

Step 7

Coat the primed plastic with tempera paint using the cleaned paintbrush. Wait four hours for the finished plastic to dry.

Tip

If the tempera-coated plastic is located outdoors, apply a coat of protective paint sealer, using the latex paintbrush, to provide extra durability in varying weather conditions.

Warning

Never apply primer over non-abraded plastic, or the finish will peel.

Do not apply tempura paint over unprimed plastic, or it will eventually flake off.