iDye comes in 38 colors - 30 colors for 100% natural fabrics (such as cotton, silk, rayon, wool, and linen) and 8 colors for polyesters and nylons. (CAREFUL, all Polyesters and Nylons are not created equal, and not all will dye as desired or even at all). It is great for quick and easy dye jobs and easy for beginners.Each iDye packet contains 14 grams (about 1/2 oz.) of dye powder and for lighter colors one packet will dye at least 2 to 3 pounds of fabric in 30 minutes. For black or darker colors more intense color better color fastness blends and synthetics Jacquard suggests that twice the amount of iDye be used and that the garments be simmered on the stove to provide the best results. The new fixative can be used in the washing machine as well.