@FloBear - The Silk Society is where we get our silk for making C17th 'colours', ie, 6ft square flags. Apart from the fact that silk will stretch on the bias at the slightest provocation and needs immediate stabilisation, I don't have problems with it.
Silk Society stuff is excellent but pricey although, from the sounds of it, you don't need a lot.
https://www.thesilksociety.com/I've been cutting out patterns that haven't yet had their excess tissue trimmed away for years and it doesn't dull the shears. Wouldn't ever use my shears on any other kind of paper, though.
Finally, Gutermann sew-all polyester works well on silk, I find.