Colored pencil artists who enjoy watercolor pencils will get the paper damp or wet in some areas. Sometimes a good portion of the paper will become wet if doing a wash for a background in watercolor. If an area of paper is wet, it will expand and leave a bump which can cause difficulties later with continuing drawing on an uneven surface or the warping could make framing difficult.
When paper has been wet, cockling (or buckling, warping) will occur. Paper can be stretched prior to using to resist the buckling. Watercolor artists will stretch their paper after sizing. Stretching paper will make it remain flat.
Stretching involves soaking the paper until it expands and attaching the wet paper to a support to dry. Paper that is over 300 gsm does not need to be stretched unless you soaked it to remove sizing.
For small amounts of water used in small areas, I have found that having the paper taped to my board with an artist tape and drying it flat is enough to provide the support that stretching needs.
To stretch paper when a lot of water will be used:
- Soak lightweight papers for 4 to 5 minutes in water, avoid creasing. Remove paper from the water and let excess drip off. Lay paper down on a clean board and apply gummed paper strips around all four sides. Leave the board laying flat.
If your paper is warped after stretching it, a few things could have gone wrong.
- If your board is stood up to dry, the water will run to the bottom and pull the paper resulting in warping.
- Do not use tape not designed for stretching. In most cases, it will not stick to wet paper or will lift off while the paper dries.
- Over-moistening the strip of gum can result in it being wiped off which will prevent it from sticking.
- The paper was not soaked long enough.