Burn Test - is this really silk?

By the time I had experienced a lot of hassle with the sandwashed silk for Helen's dress, I was convinced that this fabric wasn't silk or at the very most was a polyester with some silk in it. I've written a post about making the dress, which is now finished, but I won't be posting it until after Christmas, just take my word for it that this fabric was a beast and we rechristened it 'tissue steel'.

I’ve seen burn tests carried out so I thought that was the best thing to do here.

While I was out, David jumped the gun and carried out the test. No polyester globules, just an ash suggesting silk. All of the following applied:

Burns slowly and shrinks or curls away from the flame. Will not stay lit after flame is removed. Very little smoke is produced but it smells like burnt hair (wool) or feathers (silk). Ash is a gritty powder or a dark brittle, easily crushable bead.

From Dharma Trading website

David didn’t take photos but I don’t really see any need to repeat the test to get those.

It seems certain that what I have is silk, presumably just not very good quality silk, which is evident from the uneven dyeing and excessive slubs in some places, while the rest is smooth, as smooth as sandwashed ever is.

There is downloadable chart about the results of burn tests on common fabrics from Threads at:

https://images.taunton.com/downloads/th/T168_Burn_Test_Chart.pdf

It’s often important to know what exactly your fabric is, particularly should you wish to dye it.

I had to get on and finish the dress despite my disappointment in the fabric. I’m considering whether I should buy some peachskin fabric for the next rendition? Any thoughts?