A colorfast fabric does not bleed, fade or change when washed or cleaned with a product or in the washing machine. Testing for colorfastness is an essential step in cleaning any fabric. Whether you plan on washing a new pair of jeans or spot cleaning an upholstered chair, knowing how your fabric will react to the product in which you are going to use is essential. It will also a prevent a possible disaster in the washing machine when colors from one garment can bleed onto all the other clothes in the same load.
Find an inconspicuous spot on your fabric, such as the inner seam of a shirt, the backside of a sofa skirt or the carpet area in the closet.
Wet a white paper towel or rag with the product, such as a fabric cleaner, in which you are planning to use on the fabric. If you are planning on washing a new piece of clothing, just test it with water.
Blot the fabric with the towel or rag and look to see if any colors transfer from the fabric to the towel or rag. If the fabric doesn't bleed, proceed to the next step for more testing. If the fabric bleeds onto your towel or rag, stop. It is not colorfast.
Spray the fabric in the inconspicuous spot with the product you are going to use. Let it soak in for two to three minutes. Blot with the towel or rag to see if any colors transfer. If you are planning to wash a solid colored fabric, you can swish it around in a sink full of cold water to see if it bleeds.
Examine the fabric as well to see if the colors spreads or fades or if the material reacts in any other way to the product used. It may need to professionally cleaned. For solid colored fabrics, wash them separately or by hand until they no longer bleed.