Cursed Colored Envelopes

How to safely remove stamps from the cursed colored envelopes?

You could try using humidity but there is always the chance the moisture will cause the envelope dye to leach into the stamp paper. Place the stamp above a pan of water in a tightly closed container, give it a day or two. If it was a rare stamp I would not attempt it.

Perhaps simply trim the paper close to the stamp and call it done?
Don

Supposedly a little salt in the soaking water will reduce the amount of color extracted from the envelope paper.

If you have only a few such stamps to soak, you might want to put then under the tap with a slow stream of water. Thus the color would be washed down the drain rather than soaking into the stamp. Only worth doing for stamps that you really, really want to remove from the paper.

With salt. Colour paper pieces that are white one side coloured the other are the better ones to work with but those black, blood red and electric blue etc on both sides I use heaps of salt. As soon as the colour starts to come away from the paper you need to get that stamp off.

Experiment 1st with damaged coloured paper stamps. But if you get a bit of staining a very weak mix of water and a very small amount of bleach before the colour stain dries is helpful.After using bleach soak in water with a bit of detergent to get that bleach out of that stamp quick as.

Tks all for your suggestions.

I use a similar approach, if the stamp is scarce, otherwise I pass coloured fragments on.

My success rate would be say, 1 in 8 remain stained to some degree.

PS: I soak by dropping the fragment lightly on top of cold water, stamp face up.
(No dish liquid, as that destroys the surface tension)
Hopefully the water soaks through the coloured paper, before hitting the stamp
and you can lift off, give it about 20 minutes.

So far so good with the salt and light bleach bath after. I would say approx 90% are keep-able.
UK out of the way now US and Canada, loads to do, but helps the Winter months pass.