Canvas is a popular fabric because of its durability. It is used to make shoes, furniture, boat and car coverings, among other things. Although long-lasting, canvas can get dirty, stained and even mildewed as it is used. No matter the product it was used to make, however, canvas can be cleaned with a little detergent and water. Chemicals such as non-chlorine bleach can be used to remove stains, but it might compromise the integrity or colour fastness of the canvas.
Use a stiff, dry brush to brush away any caked dirt.
Place removable canvas furniture covers and certain canvas shoes in the washing machine. Use gentle washing powder, cold water and the gentle cycle. Then air dry your canvas product. Not all canvas material--especially material that has been weatherproofed or otherwise treated--can be placed in the washing machine. Check the product's label or contact the manufacturer before placing any canvas item in the washing machine.
Clean non-machine washable canvas by mixing 1/4 cup of mild, bleach-free liquid detergent soap (use non-detergent soap for weatherproofed or otherwise treated canvas) into two gallons of warm water (for smaller canvas items like shoes, simply add a few drops of detergent onto a wet cloth and scrub). Then dip a sponge in the solution and wipe or lightly scrub the canvas clean.
Remove light stains from canvas by adding the detergent used in Step 3 directly to the stain. Leave it to soak for 5 minutes, then scrub the stain out with a scrub brush. Or, make a paste of baking soda and water and apply it to the stained area. Leave it for 10 minutes, then wipe away with a clean damp cloth.
Clean heavily stained canvas by scrubbing it with a brush dipped in a solution of 1/8 cup non-chlorine bleach mixed into one gallon of water. If a weak solution does not completely remove the stain, increase the concentration incrementally. If that does not work, spray the stain with a chlorine bleach spray cleaner or mildew remover, then scrub. Wet the canvas thoroughly with water before treating it with any bleach solutions to minimise damage. Be aware that bleach is likely to damage the canvas, change its colour and strip any treating it may have.
Rinse the canvas thoroughly with cold water after hand washing it with any of the methods listed above.
Allow all canvas to air dry. Never put it in the dryer.
Periodically spray your canvas with a solution of one part white vinegar to one part water to prevent mildew build-up. If not already treated, spray outdoor canvas with an outdoor-fabric protector and water repellent. If your canvas shoes lose their shape after you clean them, stuff them with newspaper to support their original shape as they dry. Clean salt stains as soon as possible or they may crack your canvas.