I have 2 pairs of floor-to-ceiling-length blackout curtains. They were originally a mid-blue, I dyed them dark brown a couple of years ago with machine Dylon, and now I want to dye them a kind of mustard yellow. Would it be possible to bleach them light enough to re-dye them? How do I do it? Will they fall apart (they're getting on for 20 years old but were good quality when bought)?
Dylon sell a product which removes some colour before you dye, but how successful it would be I do not know. You could try it but it might not work and they might be ruined. You could try just bleaching them, but how successful that would be I don't know - maybe do a test on a bit of the hem?
Tbh you have had them for 20 years they don't owe you anything so why not get something new instead?
The problem with bleach is getting it even enough, it will probably go a bit blotchy. You could try a really dilute bleach solution, pre-soak the curtains, and put them in a large container so you can stir while it takes? Bit of a risk though. What's plan b if the bleach destroys them?