A sheet of watercolor paper has the naughty propensity to warp due to moisture. The remediation in a few words.
When painting, a watercolorist is required to make wash, wetting the paper and applying diluted paint(wet on wet Technique). With these water supplies, paper tends to curl if not before. Bumps and depressions are formed, and influence the mixture of the pigments into the water, especially if the support is flat. In general, it is not desirable and can actually ruin a picture.
In addition to the quantity of water, other criteria increase the curl of a sheet:
- Paper quality: Ligthest sheets curl more easily, it is advisable to opt for a weight of 250 to 350 g/m², but there are varieties of paper from 400 to 700 g/m². The compound of cotton paper are also more sensitive than those composed of vegetable fiber.
- Paper size: The sheets with a size over 20cm side are guaranteed to curl, which demonstrates the frequency of this phenomenon!
Finally, even if the paint is still possible on vertical plane, the paper may curl and then need to be flattened. We can then either moisten the blank side of the sheet, or hire a professional that is equiped in accordance.
A simple solution is to use a block glued on the 4 edges. This is no problem on the 30CM and beyond depending on the brand, however, it happens that the paper comes off anyway (on the format 40 X 60 CM with Arches paper, yet one of the best). And then ... Not easy to recover!
So for others, it is necessary to wet the paper and handing it on a plate
Wet the paper
The easiest way is to soak the sheet in a bath for 5-8 minutes.
The bathtub must be cleaned and rinsed especially to avoid distorting the paper by the absorption of detergent.
An alternative technique is to wrap the paper in a plastic transport tube (cost some € in a specialty store) and fill with water. Enclosed a link to the article of an artist who is using this technique.
Gummed strips and pins
On small formats, watercolor set bands craft paper tape on the edges, and then plant special pins.
For my part, although I tried this technique, it has NEVER worked:
- Paper strips come off when drying
- Pins become flattened by planting the wood and do not hold the sheet evenly
- On wet paper, they can damage the sheet
A variant is rub the paper, ie glue the edges of the sheet behind the frame, but the glue can damage the sheet and the technique is complex.
Other watercolorists stretch the paper to the edge of their board. For your convenience, you can use a special stretcher.
The disadvantage of this technique is the need to have as many stretcher as various sizes of paper.