Back in 2011 when I started dyeing more seriously, I bought a jar of black acid dye. Overdyed a pink/green/white skein immediately and got a beautiful deep black.
Over the last few months, my “black” dye jobs have been increasingly erratic; in one case I tried to overdye a solid brown to black, and got a mottled brown/grey. In another case, I tried to deepen the tint of the yarn shown on left, and got the yarn on the right.
During this week I took a skein of pure white mink yarn and put it in a solid black dye bath. Even though the dye did not exhaust, this is what I got.
Now, the jar is 3 years old. So I emailed Jacquard to see what they’d say. Apparently if you make it into dye stock (in solution), it stays good indefinitely, but the powder in the jar can expire due to airborne contaminants!
Since I only dye once every couple of months, making up dye stock seems ridiculous. I’ll just start buying the 2-ounce jars from now on. BLEAH!