I bought a cheap 18th century style wallet/billfold at a rondy. It's actually well constructed, machine sewn, and an attractive reddish brown color. But the first time it got really wet (sweat) the colors were running. Then last night it got really wet and it stained all the dollars and checks inside. This reminded me how many times I have gotten leather where the dye leaches out when wet. On this one, I washed it several times last night in soapy water, water with baking soda, water with vinegar, whatever I could think of to either get all the dye out or fix it in place. No matter what I did, more and more dye leached out. I got to diminishing returns, dried it overnight and this morning waxed it with neutral shoe polish.
Couple of questions.
1) is there a way to know if pre-stained or dyed leather is going to leach color?
2) Is there a way to fix the color if it's inclined to do this?
3) Is there a sure-fire way to get all that dye out so it won't leach again?
4) For staining leather on projects, what types of dyes leach so badly and should be avoided?
Obviously it is possible to dye leather and not have it leach. Black shoes and white socks, for example.