Acid dyes are made for dyeing wool, silk and nylon and no other type of dye does it better. If you have skeins of yarn or yards of fabric to dye, this is the type of dye you need. These powdered dyes are intended for tub-dyeing yardage, yarns or clothing. They can also be used for painting but they're not our first choice. If you intend to paint on silk or wool, you can choose one of our other silk dyes from the website, or see the manufacturers directions for painting it on and steaming it. You can use these dyes either on top of your stove or in a washing machine (have to get the water pretty hot). The only other thing needed is a little white vinegar from your pantry or some other mild acid like Citric. Acid dyes are very economical, as they react fast, they exhaust well and the results are Very Permanent- light and wash fast! Because they exhaust so well and can be used with household vinegar, they could also be considered to be a "low impact" dye.1/2 oz. dyes up to 2 lbs. of dry fabric, depending on the depth of shade desired. If going for a specific shade depth, test!