Before starting to paint, it is necessary to set up the paper on your board. I use a field sketch board which is a large Masonite board approximately 21 inches x 25 inches. These can be purchased at any art supply store. Since I usually have several projects going at one time, my husband has made me several boards out of Masonite panels which he purchased at a home improvement store, cut to size, and rounded the corners.
Tip: If you are a beginner and don't want to purchase a sketch board, a large cookie sheet can be used. Do not use a nonstick or Teflon cookie sheet as the masking tape used to hold the paper in place will not stick to a nonstick or Teflon surface. An inexpensive cookie sheet can generally be found at dollar stores - these work great.
The watercolor paper is taped to your board before painting to hold the paper in place and help prevent buckling when wet. If you are using a cookie sheet, tape your paper to the back side of the cookie sheet. I use masking tape and tape all 4 edges of the paper securely in place, taping approximately 1/4 inch on the paper. The tape will remain in place until the painting is completely dry. Artist tape can also be used; however, it is generally more expensive. I find that masking tape works just as well.
Tip: Before applying the tape to the paper, tear strips the length of the sides of your paper and stick them to your clothing. This will "grab" some lint, make the tape a little less "sticky" and prevent the tape from tearing your painting when it is removed.
See photo above of prepared sketch board. For most paintings, I do not use an easel. I paint on a flat surface and can elevate the board as needed if I would like to force the paint to run.
On my next entry, I introduce beginning watercolor techniques.