About the Dyes

choosing the right dye for your fiber
Your choice of dye depends directly on what kind of fabric you are using. You'll get bad results if you use a wool dye on cotton, or a cotton dye recipe on wool, or either on polyester.
Dyes for Cellulose Fibers
These are your choices if you want to dye a t-shirt. Cellulose fibers include cotton, linen, rayon, hemp, ramie, lyocell (Tencel), and bamboo.
Fiber Reactive Dyes (best choice)
Direct Dye (hot water dye, less washfast)
Vat Dyes (more complex method)
Naphthol dyes (more hazardous, less available)
All purpose Dye (hot water dye, less washfast)
Dyes for Protein Fibers
Protein fibers include all fibers made by animals: wool, angora, mohair, cashmere, as well as silk. Silk is the only non-hair animal fiber, and can be dyed like wool or like cellulose fibers, above. The high-pH recipes used for most cellulose dyes will ruin animal hair fibers.
Dyes that can be used for protein fibers include the following:
Acid dyes
Food coloring
One Shot Dyes
Reactive dyes used as acid dyes
All purpose Dye (contains acid dye)
Natural dyes (these work better on wool than on cotton)
Lanaset/Sabraset dyes
Vat Dyes Also see Dyes for Protein Fibers.
'Soy Silk' is a new plant fiber, but, because it is made from soybean protein, it should be dyed like animal fibers, instead. Like real silk, it can also be dyed with fiber reactive dyes.
Dyes for Synthetic Fibers
PolyesterPolyester requires the use of disperse dyes. See Disperse Dye for Polyester.
Nylon
Surprisingly, nylon, which is a truly synthetic fiber, happens to dye quite well with the same acid dyes that work on wool and other animal fibers, in addition to dyes that work on polyester. For more information on dyes for nylon, see Dyes for Protein Fibers. You'll want to test a swatch before committing yourself to the project, as nylons vary. Nylon can also be colored with a type of fabric paint called 'Pigment dye'.
Spandex
Spandex can be dyed with metal complex acid dyes, but it is much more common for hand-dyers to dye only the cotton portion of a cotton/spandex blend. Polyester/spandex blends cannot be dyed. See How to dye spandex.
Acetate
Acetate, also known as rayon acetate, requires the use of disperse dye. (The other type of rayon, which is a cellulose fiber, is also known as viscose rayon.)
Acrylic
Acrylic fiber can be dyed with disperse dyes or with basic dyes. See Dyeing Acrylic with Basic Dye.
Ingeo
Ingeo is the trademark for a new synthetic fiber, polylactic acid (PLA), made from corn. It is dyed like polyester, using disperse dyes, though it is evidently somewhat less washfast.
Polypropylene
Polypropylene (Herculon, Olefin) is dyed while still in liquid form, before it is extruded into a fiber. It cannot be dyed at home.
Dyeing blendsMost cotton/polyester blends are best dyed as for cotton, using fiber reactive dyes, leaving the polyester undyed. Cotton/nylon blends may be dyed with all-purpose dye, or by successive dyeing with a fiber reactive dye such as Procion MX, first with soda ash at room temperature to dye the cotton, then in hot water with vinegar to dye the nylon.