Important notes regarding Dyeing Cashmere and other fine wools
  • I get questions about dyeing cashmere all the time. People are understandably worried about ruining a very nice and expensive fiber. The general note I would say about dyeing is that first don't dye something if you have very very specific needs in color outcome and cannot bear to make a mistake. Dyeing is not always 100% successful, and color can vary from fabric to fabric and can depend on what the sheep has eaten, let alone differences in the manufacturing process. There is always risk involved.

    That said, it is possible to have great outcomes with acid dyes and Cashmere. Luckily acid dyes are among the most even of dyes, and their color reproduction is very reliable even if the fiber is not.

    The largest risk in dyeing wool and especially cashmere is damage to the fiber mostly in the form of felting where the elasticity of the fiber is compromised and shape of the garment can be ruined. The largest culprit in felting is fast changes in temperature. You never want to go from hot to cold quickly, so raising your acid dye bath to 180 degrees F and then plunging the garment in cold water is a major mistake. You want slow changes in temperature, so the best thing to do is a quick transfer to hot water from the dye bath and then transition slowly to cooler and colder temps. fabric should always be added to the dye bath wet, and you should add the fabric when the dye bath is just getting hot around 100 F or so. Bring the temp up slowly over the course of an half an hour.

    One other mistake is letting the cashmere cool in the dye bath itself. The problem here is that as the temp drops, the dye becomes less soluble in the water and can adhere to the wool, leaving cloudy areas. That is why you should transfer the cashmere to warm water once the dye job is complete. Hope this helps.