Q&A for How to Dye Polyester

Use your sink or bathtub. Just add a pot of boiling water to get the water hot enough.

No. You would first have to bleach the fabric until it is practically white, depending on the shade you are attempting to achieve in your end result.

Never use dye containers as food prep afterwards. Many ingredients in commercial dyes are toxic. Wear gloves and particle masks if using powdered dye. Keep all dye containers separate from any other use by either labeling them clearly or disposing of them afterward.

Yes, and it should work just fine.

If you want black, then you'll probably be fine if it's a light shade of yellow. If you want to turn it fuchsia, then you're going to need to bleach the dress the whitest you can get it to be and then buy dye.

It can, but it's best to use dye. If you need to use paint, be careful of the kind you choose. Some paints, like tempera, flake off once they dry.

Dye it dark red. You should end up with a black dress provided that the fabric can hold more dye. Fabric does reach a point at which it can't absorb any more dye.

RIT dye can stain so test the dye on an inconspicuous part of your sink or washing machine before use.

If it could work, it could only work on cotton. Henna requires a protein to dye for it to work. With henna, black is achieved with (100% pure) henna by using red henna and then indigo. If only indigo is used, it'd be blue. As for fabric, it might work if done this way, but I've never used it for that. My knowledge is based on lots of research and use of henna myself. Check out henna.com for more information.

You could either use black dye with more water, or buy gray dye (if it's possible).

Dye can only work if it can penetrate the fabric. Assuming your umbrella is currently waterproof, the dye would not absorb into the fabric, and if it could it would no longer be waterproof, which would not make for a very good umbrella. It would probably be cheaper to just buy a black umbrella.

Possibly, but you might need to dye it multiple times, depending on how dark the colors are.

Synthrapol is a special detergent used in pre-scouring fibers before dyeing, and in washing out fiber reactive dyes after dyeing. It is also sometimes used as a surfactant, or wetting agent, to improve dye penetration. You can buy it on Amazon for about $20 for a quart.

You'll want to use a cotton dye and a synthetic dye from the same company for a similar formulation, or it may come out light. Both dyes get added to the same pot.

No you cannot. You will have to use bleach it or use a color remover first to try to get it as light as possible as the fabric can only hold a certain amount of pigment. After that you can dye it.