How To Stretch Watercolor Paper With Staples. When you soak the paper it expands. Water, stapler and staples, masking tape or artist's tape, watercolor paper steps:
And there are always alternatives. Your 1/2″ thick foamboard, stapler (full of staples), paper towel roll, and a double layer of paper towel laid out on your work surface. I like to just tape the dry paper right down to my work table.
Gum paper works for smaller sizes but always gives me problems with a full sheet size.
Often, after the staples are removed, i put a straight edge on the line of staple holes and cut off the excess with the mat knife. Now repeat the other short side. This system will leave no holes in the deckle, and is easy enough to use that artists of all ages will be delighted. And there are always alternatives.