Watercolor papers come in different forms, qualities, surfaces, and weights, all of which respond differently to the paint and to various painting techniques. To determine which paper is best for your needs, first, it is useful to understand the characteristics of paper and what makes papers different from each other. Then, it is helpful to experiment with different watercolor papers to see what works best for your painting style and subject matter. There are many excellent watercolor papers on the market, and finding the paper that you like best is as important as finding the paint that you like best.
Like many art supplies, paper comes in a variety of qualities, from student grade to artist grade, and the choice of paper for a watercolorist will greatly influence how the paint handles and what kinds of brush marks can be made.
Watercolor paper can be made by hand, by cylinder-mold machines (referred to simply as mold-made to differentiate from machine-made), or by machine. Papers made by hand have four natural, or deckle edges, and the fibers are randomly distributed, making the paper quite strong. Papers made by mold have two deckle edges. The fibers are also randomly distributed, which makes it strong but not quite as strong as handmade. Machine-made paper is made on a machine in one continuous process, with the fibers all oriented in the same direction. All the edges are cut, although some have artificial deckle edges for a more authentic appearance.
Machine-made paper is less expensive to manufacture and purchase, but most artist-quality watercolor papers on the market are mold-made rather than machine-made.
Always use the highest quality paper you can afford, the best of which is artist-quality paper. All artist-quality paper is acid-free, pH neutral, 100 percent cotton. That means that the paper will not turn yellow or deteriorate over time, unlike lower-quality paper made of wood pulp, such as newsprint or brown kraft paper.
Handmade papers are usually sold in single sheets. Mold-made and machine-made papers can be purchased in single sheets, packs, rolls, pads, or blocks. The blocks are pre-stretched watercolor paper sheets that are bound on all four sides. When you have finished a painting, you use a palette knife to remove the top sheet from the block.
Mold-made and machine-made watercolor papers come in three surfaces: rough, hot-pressed (HP), and cold-pressed (CP or NOT, as in "not hot-pressed").
Rough watercolor paper has a prominent tooth or textured surface. This creates a grainy, speckled effect as pools of water collect in the indentations in the paper. It can be hard to control the brush marks on this paper.
Hot-pressed watercolor paper has a fine-grained, smooth surface, with almost no tooth. Paint dries very quickly on it. This makes it ideal for large, even washes of one or two colors. It is not as good for multiple layers of washes, because there is more paint on the surface and it can get overloaded quickly. It is good for drawing and for pen and ink wash.
Cold-pressed watercolor paper has a slightly textured surface, somewhere in between rough and hot-pressed paper. It is the paper used most often by watercolor artists because it is good for both not only large areas of wash but also as fine detail.
The thickness of watercolor paper is indicated by its weight, measured either in grams per square meter (gsm) or pounds per ream (lb.).
The standard machine weights are 190 gsm (90 lb.), 300 gsm (140 lb.), 356 gsm (260 lb.), and 638 gsm (300 lb). Paper less than 356 gsm (260 lb.) should be stretched before use; otherwise, it is likely to warp.
How much paint you'll use (and how much water) influences what weight you'll need. Paper that's 90 lb. is likely too thin for anything but practice. If you want to experiment, look for an assortment pack.
Of course, if you're just practicing, you may want to have less-expensive student-grade cellulose-based pads on hand so you don't have to use up your expensive paper as quickly. Cellulose-based paper will yellow over time, but practice pieces aren't anything you'll frame anyhow.
That said, don't go for the cheapest paper out there, as it may be difficult to work with and not give good results—and then you don't learn how the paint acts with the more textured paper.
You could also practice on smaller pieces of artist-quality paper (buy a roll and cut it) or attempt to wash practice paints off by the immersion of the page in a tub of water or by running it under a faucet, before laying it flat to dry. (That might not work on lower grades of paper, and it won't work on artist-grade papers forever.) You can also use both sides. Dig out those early pieces you don't want to look at now and paint on the back.
- Watercolor paper differs from manufacturer to manufacturer, so experiment not only with the different kinds of paper but also with various brands of paper.
- Watercolor paper is usually white, but it need not be. A variety of cool and warm tints is available.
- Use acid-free paper for paintings you wish to keep, as this type will yellow less with age.
Updated by Lisa Marder