let me introduce you to the secrets for successful dyeing with ripp first of all know your fabrics check the fiber content on the label of the item you plan to die RIT is a user-friendly diet that will color most fabrics including cotton linen and rayon as well as nylons silk and wool it will also die blends up to 60% cotton however it will not die 100% polyester as a guideline we recommend that you use one box of red powder or a half a bottle dye and that will color up to 16 ounces or one pound of dry weight fabric 1 pound of fabric is about the weight of a bath towel 3 yards of cotton broadcloth or 4 ladies medium-sized t-shirts always use hot water in your dye bath ideally it should be about 140 degrees if you think your tap water is not that hot then heat some water on top of the stove and add that to your dye bath another secret to achieving bright intense colors is to add salt or vinegar to your dye bath if your dyeing cotton fabric then we recommend adding one cup of salt if you're dyeing wool nylon or soap then add one cup of white vinegar to your dye bath always pre-wash whatever it is that you plan to die that helps to remove any finishes that may interfere with the dye process we recommend using a liquid laundry detergent that's high in soda ash such as fat you