artwork by Erik Davis

What does it mean to stretch watercolor paper? Why & how should it be done?

Many artists soak or stretch their watercolor paper prior to painting. This is typically done on lighter-weight watercolor sheets to stop the paper from buckling when wet media is applied to the surface.

When watercolor is added, the moisture causes the surface to expand slightly on the wet side. The other side remains dry, causing bowing and buckling. This can be difficult for the artist to work with because the paint pools in valleys on the paper. Typically lighter weight sheets are more susceptible to buckling with heavy applications of water.

To resolve this issue, watercolor paper can be “soaked and stretched” so it remains completely flat when the artist begins painting.

Method 1 – Stretching paper to use later

Supplies:

• Watercolor paper
• Large clean tray for water: tray should have one dimension slightly longer than the smallest dimension of your sheet. For example, if you’re using an 11”x15” sheet of paper, your tray should be just over 11” on one side
  • If you don’t have a tray, you can use a spray bottle instead
  • Clean water
  • Gummed paper tape/ butcher tape
  • Paper towel or a sponge
  • Sturdy, uncolored board that won’t bend or warp that is just larger than your sheet – examples:
    • Polystyrene Board
    • Gatorboard
    • Plexiglas
    • Lexan

1. Soak the sheet in a tray of clean, cold water. If your entire sheet does not fit inside the tray, hold the sheet at both ends and dip one end into the water. Pull the sheet through the water multiple times until each part has been fully submerged and the sheet is evenly soaked. If your sheet fits completely in the tray, set it inside to be fully submerged in the water. Sheets that are 90lb/190gsm or lighter can soak for about 3 minutes. Sheets that are 140lb/300gsm or heavier can soak up to 8 minutes.
   
   Do not touch the surface of the paper while it is soaking. The paper becomes more fragile when wet and the oil from your fingers can show up as finger marks on the final painting. Consider wearing latex gloves during the soaking process. 
   
   
2. Carefully drain the water and place the soaked sheet on a clean, sturdy board.
   
   
3. Use a clean paper towel or sponge to blot excess water from the sheet.
   
   
4. 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). Place along all four outer edges of the paper, covering just about ¼” of the paper.
   
   
5. Let the paper dry overnight. Once the paper is dry, it will be stretched tight on the board and will not warp when watercolor is added. Create your painting while the sheet is still taped to the board. After your painting is completely dry, cut away the taped edges using a ruler and an X-acto knife. If you want to keep the existing edge of the paper, you can re-wet the tape and very carefully pull it up from the paper. 

*If you don’t have a tray to use, you can place the sheet directly on your clean, sturdy board. Use a spray bottle with clean water to fully soak both sides of the sheet. Then follow steps 3-5 above.

Method 2 – Stretching paper to use immediately

Supplies:

• Watercolor paper
• Large brush
• Clean water
• Paper towel
• Sturdy, uncolored board that won’t bend or warp that is just larger than your sheet – examples:
  • Polystyrene Board
  • Gatorboard
  • Plexiglas
  • Lexan

 Lay your sheet of watercolor paper over the board.

1. Using a large brush, saturate the front of the sheet completely with water (you can’t use too much, so be generous). Turn the paper over and do the same on the back side.
   
   
2. Turn the sheet back over and let it sit face up for about 15 minutes.
   
   
3. Roll 2 layers of clean paper towel over the sheet of paper and firmly press on all areas of the sheet to soak up any excess water.
   
   
4. Start your painting while the sheet is still damp.