Name: Samuel
Message: I'm a paramedic who desperately needs to dye black a pair of 65%polyester-35%cotton emt pants that are Dupont Teflon coated. What exactly should I use? They are $70 pants. Thank you for your time.

I'm sorry, but the Teflon coating, which is designed to repel stains, will also repel dye. It is very unlikely to be possible to dye your pants black. The Teflon will prevent any dye from achieving a solid dark color.

65% polyester/35% cotton pants cannot be dyed black, anyway. While the 35% of the fiber that is cotton is easy to dye black, or any other color, using cool water fiber reactive dyes such as Procion MX dye, dyeing only one-third of the fiber in a garment black can produce only an overall grey color, not black.

However, dyeing the 65% of the fiber that is polyester requires extensive boiling with a special kind of dye called disperse dye, plus a noxious carrier chemical. The boiling must be done in a non-aluminum cooking pot which is large enough for the pants to move freely in, or else the color will be uneven. A cooking pot that has been used for dyeing cannot be used for food again, however, and is likely to be quite expensive - more expensive than a new pair of pant! Furthermore, boiling any ready-made garment for an hour is likely to damage it. It's far more damaging to boil fabric than to wash it in hot water.

It is easy and fun to dye 100% cotton items that have not been treated with a dye-repellent coating, but articles such as your Teflon-coated pants are just not suitable for dyeing.