another case of pre-washing and testing was needed.
i know the whole pre-wash/don't prewash topic is on-going and futile; but there are times when you should ALWAYS pre-wash. and one of those times is ...
when ever you plan to use an (additive)
if you plan on marking, fusing, starching, dyeing, painting ect, ect...you should pre-wash your fabrics that way what ever technique you are using is not going to be adversely affected by any chemicals or oils in the fabric. and you should always test any (marking-tool) on each fabric being used, if you use 50 different fabrics in a quilt but only check your chalk on 2 of them you have no idea if it is going to come out of the other 48. some of the dyes in chalk are harder to remove than others and when they (react) with the chemicals in the fabrics you never know what is going to happen