Palettes are available in different shapes and sizes and are made from a wide range of materials including: wood, acrylic, plastic, glass, aluminum and disposable paper. There are also paint mixing trays and cups for watercolors. Choosing a palette that's best for you is a matter of personal preference. Considerations include the paints you use and how large a mixing area you need. Consider also whether or not you want to hold your palette while you work, as in the case of the classic kidney shaped palette with thumbhole. Some artists prefer to keep their hands free and work with a flat lying palette stationed at the proper height on a table. One advantage of a hand-held palette is it allows you to move about the studio and view you artwork from different angles while continuing to mix paint. An enameled butcher's tray also makes a good palette as it has a hard smooth surface that is easily cleaned.
Oil and acrylic paint can be used successfully on any palette surface. If covered with plastic wrap, oil paints can keep for a few days. When out of their tubes, acrylic paints have a relatively short life span. They can be covered in wrap as well, and sprayed with water from a spray bottle for a not-so-long, but longer life. Stay Wet Palettes are an alternative type of palette that helps acrylic (or other paints) last longer.
Traditionally, watercolors work best on palettes that have slanted wells, shallow dishes and/or mixing areas. Some watercolor artists prefer a palette with one large mixing area surrounded by little compartments. Others prefer to have several small wells for each pure color, and adjacent to each well, a larger one for mixing a fluid version of that color.
Stay Wet Palettes are covered palettes designed to keep acrylic paints moist and usable for days or even weeks. These palettes use a sponge-like material and specially designed permeable palette paper to keep the paint fresh. The sponge is moistened and placed under the palette paper to increase the longevity of acrylics and other water based paints. Oils and watercolors can also be kept fresh longer when stored inside these palettes. For oils, use an oil paint palette or disposable palette pad of the correct size to fit inside of a Stay Wet palette. Use of the moistened sponge is not necessary for oils.