When damp fabric objects are folded or crumpled for long periods of time, mould and mildew can begin to grow on the fabric. The mould produces a musty smell in the fabric as well as grows in tiny black dots on the surface of the fabric. If the mould spots are not removed in the proper manner, they can permanently stain the fabric. Removing mould stains from canvas can be accomplished quite easily using basic household supplies.
In a small container, such as a cup, mix a solution of 1 cup of water with 1 cup of isopropyl alcohol. Stir the solution thoroughly with a spoon to combine.
Lay the canvas item on a flat surface with the mouldy section facing upward.
Dip a white cotton washcloth or towel into the water and alcohol solution.
Place the dampened section of the towel over the mouldy canvas and rub it gently, but firmly, over the surface of the canvas. Reapply more liquid to the towel as needed, and continue rubbing until all of the mould and mildew is removed.
Rinse the canvas in cold tap water to remove all traces of the alcohol mixture.
Lay the canvas flat in a well-ventilated location to air dry.
Do not use bleach to remove the mould as the bleach can yellow the canvas.