Canvas trainers, bags and other items never seem to go out of style, adding comfort, versatility and ease of care wherever and whenever they're used. These same items take on an unappealing yellow colour when washed with bleach. Although chlorine bleach successfully removes stains from most white fabrics, canvas reacts adversely to bleach, causing yellow stains and discolouration to form. If the yellow stains have ruined your fashion-forward sneakers or functional messenger bag, you can reclaim their previous appearance with the use of simple products found around the home.
Stir 81 g (1/2 cup) cream of tartar into 1.4 litres (1 quart) of hot water until completely dissolved. Submerge the canvas item in the cream of tartar solution and allow it to soak overnight. If the item is too large to soak, saturate clean cloths with the cream of tartar solution and lay them over the yellowed area. Moisten the cloths, when possible, to keep the yellowed surface wet overnight.
Remove the canvas item from the cream of tartar solution. If the item is small enough to be laundered, wash it in the washing machine with washing powder. Wash the surface of a larger item by pouring a quarter-sized amount of washing powder onto a dampened scrub brush and scrubbing the surface. Rinse the larger surface by blotting it repeatedly with a wet towel until the detergent is removed.
Treat remaining yellow discolouration with a paste made from equal parts of water and baking soda. Smooth the baking soda paste over the yellowed canvas and allow it to soak into the fabric overnight.
Brush the baking soda paste off the surface of the canvas with a towel. Wash the canvas item again as instructed in Step 2.
Pat the canvas item dry with a clean towel. Place the canvas in a dry location to air-dry completely.
Remove small areas of yellow discolouration with undiluted hydrogen peroxide. Apply the peroxide and allow it to bleach the fabric for 30 to 40 minutes. Repeat this process until the yellow stain is gone.
Canvas is made from cotton and will shrink if placed in the dryer. Allow canvas items to air-dry instead.