The deep indigo dye that gives blue jeans their distinctive hue is, unfortunately, a major culprit for color transference. When worn before washing, new jeans can easily leave streaks of dye behind if rubbed against absorbent fabrics such as canvas. Fortunately, a denim stain is not a life sentence for your canvas fabric. By acting quickly and applying the appropriate stain-fighting aides, you can usually lift most or all of the denim dye from the surface of the canvas, returning your fabric to like-new condition.
Apply a thick layer of heavy-duty liquid laundry detergent to the stained area. Allow the detergent to sit for 10 minutes.
Rinse out the detergent under cool, running water.
Mix a solution of all-fabric powdered bleach, following the manufacturer's instructions for dilution. Soak the stained area of the fabric in the solution for 15 minutes.
Rinse out the all-fabric powdered bleach under cold, running water.
Treat the canvas in a solution of chlorine bleach if the stain persists. Before treating the entire piece, check the canvas for colorfastness. Apply a small drop of diluted bleach to a seam or other hidden area of the canvas, and allow the bleach to set for two minutes. Blot the area and check for indications of color change in the fabric. If the fabric is colorfast, soak the entire canvas piece in a diluted bleach solution for up to 15 minutes or until the stain has lifted.