Name: Cynthia
Message: I am a member of a team of volunteers who help a High School marching band. Recently will have been immeresed in a project of tie-dyeing performance flags. They are made of poly china silk material. When we tested the dye on one of the flags, the results were extremly dull.

What kind of dye did you use?

I read your information on dyeing and tie-dyeing polyester. We believe our fabric may be similar, but we are not sure. Is there ANY technique, dye or additive that may give us the results we are looking for? We appreciate your help.

"Poly China silk" implies that they are polyester, in a weave that imitates silk habotai. Polyester may be dyed only with disperse dye, whether by immersion - boiling for an hour with disperse dye and the right carrier chemical - or by painting and printing with disperse dye according to the instructions provided by ProChem, or by painting with disperse dye on paper and using an iron to heat-transfer the dye to the polyester. This is explained at Dyeing Polyester with Disperse Dyes, which includes links to the instructions for using disperse dye to do each of these things.

Dyes that are not specifically intended for use on polyester should not be used. They don't work. You must use disperse dye, purchased from a mail-order dye supply company such as Pro Chemical & Dye.

Nylon or silk flags can be easily dyed with acid dye. Cotton can be even more easily dyed with fiber reactive dye, as in the tie-dyeing instructions given on my site and the sites of the dye suppliers. Polyester is not nearly as good a choice, for dyeing, since the type of dye that must be used on polyester is more difficult to use. If you cannot find flags to dye that are made of nylon, perhaps you could have a local seamstress sew some for you according to the usual specifications, but using nylon, which is, after all, a very commonly used flag material. Nylon does require heat for dyeing, unlike cotton being dyed with fiber reactive dye, but is still easier to dye than polyester.