When choosing watercolor paper, pay attention to weight, material and texture of the paper. Weight refers to the weight of one ream of paper (500 sheets) and is usually between 60 to 1,200 pounds. The higher the weight, the less likely the paper is to wrinkle. In terms of material, choose paper that is all cotton and acid-free. Texture is determined by whether the paper is handmade or machine-made, and whether it is cold- or hot-pressed. What texture you choose is based on personal preference.
Acrylic and oil paint can be used on many surfaces, including paper. Choose a heavyweight paper that is quite sturdy so the paint does not warp the paper. You may want to use an art board, such as an illustration board rather than regular paper. Practicing on paper before painting on more expensive wood or canvas can help reduce costs.
Gouache (opaque water-color) painting can be done on watercolor paper. White or tinted heavyweight acid free paper is recommended. Decide between coarser or smoother paper and select a paper that will not warp with the application of paint. It is also possible to use illustration board.
Classical Asian ink painting and calligraphy are often done on rice paper. You can find both coated and uncoated rice paper. Paper coated with an alum solution is less absorbent but has a smooth texture. Uncoated paper is more absorbent with a coarser texture. Uncoated paper is recommended for fast, spontaneous painting with bold strokes whereas coated paper is recommended for slower, detailed and delicate painting.