I hand dyed almost 13 yards of fabric earlier in the year and did all the recommended rinsing and washing. However, I didn't really trust that the washing had removed all of the excess dye. And there is nothing worse than completing a quilt and having some of the fabric run the first time it's washed. So, I tested the pieces that I was going to use on a new quilt.
I cut a small piece out of each fabric and sewed them to a larger piece of white fabric. Then, it was sprayed with water and left to sit.
Here is what I discovered after letting it sit for an hour. You can see that all of the hand dyed blues and red had issues. Two of the commercial blue fabrics also had issues. All of the commercial red fabrics passed the test with flying colors.
When the problem with fugitive dye was discovered with this simple test, the plan of attack was to wash all of the fabrics that failed again in hot water with Synthropol and a color catcher sheet, and then do the test a second time. Here is the second test:
All of the blue hand dyed materials failed this second time and so did the red fabric. So, they were put back into hot water for another round of Synthropol and a color catcher. As you can see the color catcher is getting more and more pale, which means there is less and less fugitive dye in the water.
The last round of washing was with hot water and Retaine. I thought that I'd finally gotten all of the fugitive dye out. But, just to make sure, one last dye fastness test was run.
And, yes, finally, these 4 fabrics were ready to use!
I hope you check out the dye fastness in your materials too.