I've been looking out for new Ma Dola fabric - a royal blue cotton - to make the dress version of her costume. I hadn't found anything in the easy to get to fabric shops, not even at a higher price than I'd like to pay.
But I did find something interstate on eBay and there is up to 20m available. So I asked for a sample so I could check the feel/drape & content. The colour was ideal & weight was slightly lighter than I want, however the seller wasn't sure if it was pure cotton or not.
So Wednesday night I cut my small sample in half and did a burn test. The result was a bit puzzling cos it had a black flame & ash, but not beading nor behaving like a poly cotton blend. I admit to scratching my head in confusion. It didn't smell like poly either. So I thought I'd follow up with a bleach test.
Last night I popped the other half of the sample into bleach and it *is* 100% cotton, so I did a bit more researching on why was the flame and ash black. (Natural fibres completely dissolve in old fashioned plain bleach).
Answer: it's mercerised cotton. The chemical process (and possibly chemical residue??) causes the black flame and ash. So after years of sewing I've learned another new thing.
So I ordered some yardage of the mercerised cotton. I've realised that the ideal bodice pattern is Truly Victorian 446, but I'm not going to order it. Instead I'll use one of the mccall or simplicity costume patterns.