I've done a fair bit of RIT dyeing in the past, but recent lots I've had this issue come up.
Dyeing shapeways WSF-Polished with a strong concentration of Black RIT powdered dye (with some vinegar in a large amount of water).
The pieces got really good saturated black, but upon drying, I see blotches of bright white. The blotches seem to temporarily go away when wet, but come back on drying...
rit.jpg [ 1.43 MiB | Viewed 220 times ]
Any ideas on what is going on and potential solutions?