Name: Oliva
Message: How can i dye a 50/50 blend of polyester/cotton to get high washing fastness?

If you dye 50% cotton, 50% polyester with fiber reactive dye, such as Procion MX dye, the results will be quite washfast on the cotton, resulting in nice pastel colors. The polyester will not dye at all, but the Procion MX type dye will be quite permanent on the cotton fibers if applied according to instructions (e.g., "Immersion Dyeing in the Home Washing Machine using PRO MX Reactive Dyes"). Buy the Procion MX type dye by mail-order from any of the dye suppliers listed on my "Sources for Dyeing Supplies" page; you can buy the soda ash from the same source, or from a swimming pool supply store, and the salt required for washing machine dyeing can be purchased from the grocery store.

Polyester itself is difficult and unpleasant to dye; this is not a project for the dye novice. See "Dyeing Polyester with Disperse Dyes". It is better to dye only the cotton portion of a 50% cotton/50% polyester blend, and just accept the paler colors that result from having the polyester portion of the fibers remain undyed.