Nylon is a synthetic fiber and polyamide that, unlike polyester, can be dyed at both acidic and slightly basic pH conditions. This makes it suitable for both acid dyes and disperse dyes. Both of these processes require heat to fix the dye to the nylon, so take care when dying nylon-lycra blends, a combination that is heat sensitive. Avoid stressing this fabric combination while it is hot, so do not twist or stretch a nylon-lycra garment during the dye process.
Although nylon is a synthetic fiber, it dyes well with the same acid dyes typically used on animal fibers such as wool or silk. A color mixed from two different dyes will not, however, provide the same color hue on nylon as on wool or silk. Ask your dye supplier for advice on a specific acidic dye for your nylon garment. Smarttime.com, for instance, recommends acid dyes such as acidol E (basf), tectilon (ciba), nylosan E (clariant) and nylantrene B (crompton) for light colors and acidol X (basf) nylosan N (clariant), polare (ciba) and telon A (dystar) for medium and dark colors for nylon 6 and 66 blends.
Disperse dyes are usually used for dyeing synthetic, acrylic fibers such as polyesters and cellulose acetate. Use disperse dyes to dye nylon-polyester blends. For medium to darker shades of pure nylon, opt for acid dyes, as disperse dyes will lack wet and light fastness.
Most all purpose dyes, such as Dylon’s Multi-Purpose Dye or Rit Dye, will dye nylon. It is, however, hard to predict the color outcome of a multipurpose dye on nylon. According to Pburch.net, pure acid dyes will give you better results on nylon.
As many natural dye recipes are acid dyes, incorporating acids such as vinegar or citric acid takes well on nylon. Cochineal will dye nylon an intense red with a brownish tone, while turmeric dyes nylon a medium golden yellow. Indigo, as a rule, does not dye very well on synthetic fibers, but according to Autex Research Journal, nylon fabrics can be dyed with indigo in carefully controlled pH conditions (acidic to slightly alkaline).