Name: karen
Message: I have a lot of procion dye that I bought in the UK in 1966. Some packages are a kilo and have never been opened. Are they still good and is there a place where I can sell them?

What kind of Procion dyes are they? Are they Procion H dye, which must be steam-set on fabric, or are they Procion MX, which can be used at room remperature without steaming?

Procion H dye has a longer shelf life than Procion MX dye, since it is less reactive, but Procion MX dye will certainly have lost all of its reactivity by now. I wouldn't expect even Procion H dye to work after nearly four decades, though.

The shelf life of fiber reactive dye is normally considered to be about one year, though even Procion MX dye can often be used up to five years after purchase, if it has been stored under controlled temperature and humidity. Fiber reactive dye that is nearly forty years old will not have maintained its reactivity or original value.

However, even very old fiber reactive dye can be used as an acid dye, on wool and other animal fibers, if an appropriate recipe is used, such as ProChem's "Immersion Dyeing Wool using PRO MX Reactive Dyes" instructions at http://www.prochemical.com/directions/MX_ImmersionWool.htm . The use of these dyes on wool does not require that the fiber reactive dye maintain its ability to react so even fully hydrolyzed fiber reactive dye can be used to dye wool.

I doubt that anyone would want to buy old fiber reactive dyes for this purpose, but you could donate them to the nearest educational institution that has any interest in making a project of dyeing wool.