How To Stretch Watercolor Paper With Gum Tape. A bowl of clean water: That would be absolutely fine.
Carefully apply the tape so that at least an inch of the watercolor paper is under the tape, and smooth it down. That seems unnecessarily complicated, and over wet., risking washing the size off the paper.and the gum off the tape… i lay dry paper on a board, wet it with a wash of clean water with a 3 inch wide soft chinese brush, leave for a minute and then tape the top edge and stand the board upright on the floor for a couple of minutes, the excess water drains off and the weight of the wetted paper stretches. Lightly wet gummed paper tape or butcher tape with a sponge or paintbrush (do not soak or use too much water on the tape as it will wash away the adhesive).
To wet the gummed tape.
Measure out strips of your gummed tape along each side of your dry paper, tearing or cutting them so that each width is about 6cm wider than each side of your paper. This system will leave no holes in the deckle, and is easy enough to use that artists of all ages will be delighted. Paper can be stretched up to a size of approximately 1.5m x 2.5m but if you go beyond that, the tension in the paper will be too strong. Soak your paper taking care to blot the excess water from paper surface and edges.