Acid Dyes

 Acid dyes are used to dye protein fibers such as wool, angora, cashmere, and  silk,  as well the milk protein fiber called Silk Latte, the soy protein fiber called Soy  Silk,  and the synthetic polyamide fiber nylon.

 Acid dyes sound scary to some novices, who imagine that the dyes themselves are  caustic strong acids. In fact, the dyes are non-caustic, are in some cases non-  toxic,  and are named for the mild acid (such as vinegar) used in the dyeing  process, and  for the types of bonds they form to the fiber. Some of them are  significantly more  toxic than fiber reactive dyes, while others are even safe  enough to eat, and are  sold as food coloring.

 According to Linda Knutson's Synthetic Dyes for Natural Fibers, acid dyes fall into  several classes: 1, leveling acid or strong acid dye, 2, milling or weak acid dyes,  and 3, super milling or fast acid or neutral acid dyes. Leveling Acid Dyes have  been sold under the trade names of Kiton, Erio, Intracid, Sandolan, and Amacid,  among others; they are also the acid dye component of all-purpose or union dyes  such as Rit and Tintex, says Knutson. It's difficult now to find out which specific  acid dyes fall into which of these dye classes, however. At least part of the reason  is that the information is not always useful to the dyer.

 Levelling Acid Dyes (Kiton Dyes)

 Levelling Acid dyes (or Acid Levelling dyes), also known as Strong Acid dyes or  Equalizing dyes, are a class of acid dyes that produce a very even, single-color      solid effect. The trade-off is that items dyed with Leveling Acid dyes should not be  machine washed or washed in warm water; they should be dry-cleaned or hand-  washed in cool water. For more information, see the page Levelling Acid Dyes  (Kiton type Dyes).

  

  Wash Fast Acid Dyes 

  Wash Fast Acid Dyes are a reasonably priced collection of many different and  worthwhile acid dyes, sold by PRO Chemical & Dye, including dyes referred to in  some books as the "Nylomine" dyes. The name "Wash Fast" is a bit of a  misnomer, as some of the dyes in the group are not very washfast at all, but this  dye series has a very devoted following. See Which washfast acid dye colors are  pure, rather than mixtures? for a complete listing of the pure dyes sold by  ProChem. For a table showing the washfastness and lightfastness ratings for many  of these dyes, as well as other dyes, see What is lightfastness?.  

 Jacquard Acid Dyes

  Jacquard's acid dyes are similar to ProChem's Washfast Acid dyes; some dyes are  the same in both lines, while many others are completely different, though of  similar colors. Jacquard givesinstructions online for the use of these dyes, as well  as lightfastness and washfastness data (which can also be seen on this site in the  acid dyes table section of the What is lightfastness? page).  

 Food Coloring Acid Dyes

 The least toxic of the acid dyes are also the least toxic of all dyes: dyes that are  actually safe to eat. (Not all acid dyes are safe! Some are serious  carcinogens.) For more information, see the page Using Food Coloring as a Textile  Dye for Protein Fibers.

 Lanaset Dyes     

 Lanaset Dyes are a very beautiful range of dyes for wool that are notable for their high  degree of washfastness. Lanaset Dyes include both 1:2 premetalized acid dyes and special  fiber reactive dyes that react with wool under acid conditions. They have been selected to  work well together. For more information see the page About Lanaset dyes, as well  as "Which Lanaset dye colors are pure, rather than mixtures?".

 One Shot Dyes

 One Shot Dyes are a form of acid dye, developed by PRO Chemical & Dye. They  are also sold under the name of Country Classic Dyes. They are very convenient to  use, as all dye auxiliaries are included in the dye mixture; all you need to add are  your fiber, plus water and heat. However, the convenience increases the cost  somewhat. More provblematically, no information is available as to which acid dyes  may be represented in this series.

 All purpose dyes

           All purpose dyes can be used to dye protein fibers, because they include an acid dye in their mixture (probably Levelling Acid dyes). See the page All Purpose Dyes. Unlike cottons, protein fibers will do best with the addition of a mild acid such as vinegar or citric acid to the dyebath.