"I've looked at cloth…

…from both sides now."  According to Mam it's "Shot Silk - BUT - she never told us who shot it, or why.
I thought I'd been through all possible Drawers and hidey-holes, it appears not.

Just had an afterthought/blast from the past - a Fire Prevention tour of "Micky Sekers" factory whilst still Stationed @ Whitehaven, and not looked it up. I wonder if a "Jacquard machine/Loom" was involved?