Canvas is a tightly woven, heavy-duty fabric often used in the production of a variety of items such as tents, painting surfaces and suitcases. Although it's not possible to dye polyester or acrylic canvases, you can dye 100 per cent cotton and linen canvases if it's pre-scoured. The process for preparing and dying canvas is complex and time-consuming but possible with patience and an eye for detail.
Wash 100 per cent cotton or linen canvas in a washing machine set at the hottest temperature, along with 1/2 tsp soda ash per lb. fabric and 1/4 cup synthrapol.
Prepare the fiber0reactive dye. Per lb. canvas, mix 1 tbsp fibre-reactive dye powder with 1 tsp warm water in a glass. Mix the dye and water together with a spoon until it's the consistency of gravy. Add 1 cup warm water and 1 tbsp urea to the mixture and stir thoroughly until the dye is completely dissolved in the water. Add the dissolved dye mixture to a large bucket filled with 3 gallons lukewarm water and stir the mixture together.
Pour 3 cups non-iodised salt into the dye water and stir until the salt dissolves completely.
Stir in 2 tsp calsolene oil to the dye water.
Place the canvas into the dye water, stirring regularly for 20 minutes.
Dissolve 1/3 cup soda ash into a small cup of water. Pour the dissolved soda ash solution into the dye water over the course of 15 minutes. Be careful not to pour this solution onto the canvas; it can cause blotches.
Stir the canvas in the dye water mixture for 30 to 60 minutes. For lighter colour results, stir for 30 minutes and for darker, deeper results, stir for the full 60 minutes.
Remove the canvas from the dye water and place it in a washing machine set on cold with 1/4 cup synthrapol. Wash the canvas twice more with hot water.
Allow the fabric to air dry.
Avoid the tedious process of hand stirring by mixing the canvas and dye water in a washing machine set on agitate. For the first few washings after the dye process, wash the dyed canvas on its own to avoid staining other fabrics.
Do not allow synthrapol or reactive dyes to come in contact with your eyes or skin, and wear protective clotching such as rubber gloves and safety goggles. If affected, wash skin with soap and water and rinse out eyes for 15 minutes with running water. Contact a physician if the material is swallowed or inhaled.