Why no soda ash for cellulose fibres with idye?
  • I recently used idye for dyeing cotton and it worked great, but I was surprised that there was no call for soda ash along with the salt as a fixative. How does the dye bond so well without the soda ash (what I had always thought was the necessary ingredient)? Is all my knowledge of dyes wrong? or have you just created a new kind of magic?
  • Salonska,
    That is a great question. There are many different types or "classes" of dyes. Soda ash is necessary for fixing "fiber reactive dyes," such as Procion MX. These dyes form incredibily strong covalent electron bonds with fibers, and soda ash helps facilitate this bonding. iDye is what is know as a "direct dye." Direct dyes can be used without a fixative, becasue they do not need to bond with fibers on a subatomic level the way reactive dyes do. The upside of this is that direct dyes are very easy to use--you do not need to worry about auxiliary chemicals and, as long as the dye gets hot enough, you can use it in the washing machine with great results. The downside is that, becasue the dye does not "react" with the fiber the way fiber reactive dyes do, the color is considered less washfast (meaning it will fade faster with washing). For the most part, this is usually not something to worry about. But if you are concerned about fading with repeated washing, we do offer a fixative for iDye: http://www.jacquardproducts.com/idye.html. This fixative is what is called a "cationic" fixative. It works differntly than soda ash, but it essentially does the same thing: locks the color into the fiber and helps keep it from washing out. How cationic fixatives actually work is another story and chemistry lesson altogether. I recommend Paula Burch's site if you want to investigate this further:http://www.pburch.net/dyeing/aboutdyes.shtml