I was told this fabric was about 50 years old. It first felt like rayon, but then I thought it might be silk because it has such a beautiful sheen. When held it ignited fast, burned away from the flame, flared up then smoldered. It did not want to burn all the way and left a "skeleton". There was no chemical odor. It left a residue I could wipe away with water. When I tapped the burned part it fragmented and was soft. No matter how much more I burned it it still was soft and black. Now I'm thinking mercerized cotton, but what of the yellow residue? Is that from mercerization? From age? I appreciate your expertise! Trish
No chemical odor, and since I used a match it smelled like that. I cut off a narrow strip this morning and soaked it in cold water for 30 minutes. Strong odor of mothballs hit me. Nothing happened to the sample. I soaped it up vigorously and a tiny bit of dye released. I repeated that using hot water and nothing happened. When it was wet it felt like rip-stop nylon, when dry rayon or silk--but it felt much stronger than silk. I air dried it and burned it again, this time with a gas flame. Same results, big flare, smoldered, left a skeleton but much less yellow residue. The odor was not chemical and it wasn't strong at all--mushrooms or doused campfire--woody. I really appreciate your help!
That gloss and the woody scent sound exactly like rayon, but the black ash doesn't. Do you have a photo of the fabric from a little distance away?
I'm going to go out on a limb and guess that it is cotton weft and rayon warp. That residue? I can only guess that it is dye or a fabric treatment.