Jacquard Acid Dyes
Acid dyes are made for dyeing protein fibers including silk, wool, cashmere, alpaca, feathers and nylon. If you have skeins of yarn or yards of fabric to dye, this is the type of dye you need. These concentrated, powdered, hot water dyes produce the most vibrant possible results. 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 citric acid. Acid dyes are very economical, as they react fast, they exhaust well and the results are very permanent. 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 fiber depending on the depth of shade desired. If going for a specific shade depth, test!