Acrylic and tempera paints are both opaque water-based media, but the similarities stop there. Because of variations in composition, each of these products offers a very different range of techniques.
Tempera paints date back to prehistoric times. They have enjoyed popularity through cave paintings, ancient civilizations, Medieval art and through present times. Acrylic paints are considerably younger. Art suppliers, most notably Liquitex, developed this medium in the 1940s.
Traditionally, tempera paints consist of pigment, egg yolk and water. The egg yolk binds the powdered pigments together after drying to prevent their returning to dust. Acrylic paint uses an elastic substance called gum arabic to bind the pigment.
After drying, tempera paints may have a chalky appearance. Very thick areas may show cracking. Acrylic paint dries with a glossy, flexible finish that does not crack.
Tempera paints work well on inflexible surfaces such as wood panels. Acrylics adhere well to most painting surfaces including canvas, wood, Masonite and some papers.
Add longevity to tempera paints by finishing with a clear, artist-quality sealant. You may choose to seal acrylic paintings or leave them unsealed.