community of dyers

Lumiere fabric paint is good stuff. It contains tiny particles of mica, instead of actual metal, as pigment. I don't think it will have quite the same effect as true metallic cord. You'll have to try it and see how you like it.

Cotton is better for fabric paints than polyester is. Jacquard brand paints, such as Lumiere, are supposed to work on polyester, too, but I think you'll probably get better results on cotton anyway. It's easier for the binder in the fabric paint to stick to the rougher surfaces of cotton.

I think you might get a better effect by buying a true metallic cord, such as this Wrights Metallic Cord in gold or silver, and then adjust the color with a non-metallic transparent paint or dye. For example, buy gold metallic cord, and then dye or paint it red or orange, to make a copper metallic. I suppose this cord may be unsuitable because it's not elastic. The same seller has a stretch metallic cord.

If you use dye on the Wrights Metallic cord, it will have to be disperse dye, because the cord is 70% polyester/30% metal. I think the Jacquard iDye Poly would be the best choice since it doesn't require acid in the recipe; acid (such as vinegar) would be likely to react with the metal. I can't tell what the Berwick Metallic Stretch cord is made of. Instead of dye you could use a transparent fabric paint, such as Dye-na-flow, to alter the color. The paint would be a better idea than the dye if the cord is woven in such a way that that the metal shows and the polyester does not.

Instead of ironing Lumiere or Dye-Na-Flow to set the paint, you can, if you prefer, add an acrylic catalyst, such as Jacquard's AirFix, before using the paint. Dharma Trading Company says you can use Versatex "No Heat" Fixative for the same purpose.

-Paula