How to Stretch Watercolor Paper
The reason you need to stretch your watercolor paper is to prevent it from wrinkling or making unwanted textures in your painting. It is also easier to frame a flat painting then a wrinkled one. I have found the following to be the best way to stretch watercolor paper, so far.
These are the materials you are going to need:
140 lb. watercolor paper size 18 by 24 inches
A ¼ inch think board, 19 by 25 inches in size
Two strips of the same wood cut 1 inch by 25 inches
Two more strips of the same wood cut 1 inch by 17 inches
Approximately 30 to 40 large art clips
A tub or large sink that will accommodate the paper
Begin by filling the tub or sink with warm water about one to two inches deep. Then place the watercolor paper flat into the water. Be sure not to put paper under running water. Let the paper soak for fifteen to twenty minutes. Flip the paper over and let it soak for another fifteen to twenty minutes. Make sure you do not crease the paper. You will notice that the paper will get light spots or become lighter all over in the water. When the paper is light all over it is time to remove it. At this point you will need the towels laid out on a flat surface with no wrinkles. Drain off the excess water from the paper. Then take the paper and lay it on the towel so it is flat. Take another towel and lay it on top of the paper so it is smooth. Rub over the towel with light pressure where the paper is underneath. Lift the edge of the towel to check if the paper is still shiny wet. Once there is no shine to the paper you are ready to stretch it.
At this point you will need all the pieces of wood laid out as in illustration one. Remove the paper from the towels and lay it on the center of the nineteen by twenty-five inch wood. Take one of the longer pieces of wood and lay it atop the longer edge as in illustration two. Repeat with all other strips of wood as in illustration...