Shelf life for mixed dyes and ideas for anything expired.

[Whit]

Hey Ladies and Gents.  I have a question about the shelf life of my mixed dyes.  These dyes are shelved at room temp and don't contain thickener.  I don't want to mix the older dyes from my bulk orders with the new dyes in bulk orders because of consistancy, BUT I am way too cheap to throw away mixed dyes. 

My questions are:
How long would you keep dyes on the shelf in these conditions and still feel confindent that the colors will be awesome enough to pass for money?

What are some of the differences that time makes for these dyes?  Are there particular colors that expire quicker?  Different halos?  Faded looks?  Doesn't work well with certain techniques?

Thanks for any input!   I have almos a 1/2 gallon TOTAL of dyes that I don't want to waste.

-W 

[Releaf]

I don't keep mine at room temperature any more, but I recall that I worried about them after a week or so.  Even in the refrigerator, Dharma's Bright Green, Kelly Green and Jade will do a blue shift after just a few days.  They'll still work, but you won't have greens any more -- they all shift towards blue.  You can't tell Jade from Turquoise once the shift has occurred.  Some colors seem to keep forever in the fridge, Better Black being one I've kept for months without noticing much difference.
It's been so long since I've kept dyes at room temperature, That's all I can remember at the moment.  I'm sure others will weigh in, though.

Good luck!

[tiedyejudy]

I agree that storing at room temp will degrade the colors much quicker than if they are kept in a cool place.  I have a fridge in my garage, and during the summer months I crank it up and keep the mixed dyes in it.  Rest of the year, just keeping them in the fridge without it being on will maintain cool enough temps that I am able to use the dyes for at least a month, although, like Releaf, I find some colors fade or change.  For me, a lot of the shirts I dye are done with 'low water immersion' technique, where I pour several colors over a scrunched shirt in a container, and I'm not aiming for the bright, vibrant colors as much as I'm trying for interesting blends and organic patterns.  So I can use older dyes and still get a nice look.  But if I'm doing something like a swirl or something where I want the colors to pop, I will mix a fresh batch of colors and use them within a day or so, storing leftovers in my cool place. 

[pburch]

What are some of the differences that time makes for these dyes?  Are there particular colors that expire quicker?  Different halos?  Faded looks?  Doesn't work well with certain techniques?

How fast the dye color expires depends on which specific dyes are in the mixture. That depends partly on how reactive the dye molecule is, and partly on how old the batch of dye was already when you bought it.

Procion Turquoise MX-G does a funny thing in which the dye molecules, which are flat like poker chips, stack up together, which turns them to a bluer color, but that's rather subtle. More obviously, at the same time fuchsia (red MX-8B) and yellow (yellow MX-8G) go bad more quickly, so they become lighter in color. But, if your turquoise happens to be old, it may seem to go bad faster even though it would tend to last longer if they were all equally fresh.

Halos are mostly caused by other colors reacting more slowly than fuchsia does, so it hits the fiber right away and stays where you put it, while the other colors spread out more. You'll have less haloing if you substitute red MX-5B for red MX-8B.

Once Procion MX dyes go bad, they can no longer react with cotton and other cellulose fibers, but, if you substitute vinegar for soda ash and add heat, they will still work as acid dyes on silk or wool.

-Paula