@msbellows @douglasvb @MsMerope @cvvhrn @ai6yr Holy cow - that looks exactly like what my family used on our Christmas tree for a few years in the late 1960's. Ours was marketed under the name "Angel Hair."
It may have been healthier than the lead tinsel it replaced, but it was not nearly so pretty- there's genuinely nothing like the drape and gentle sheen of lead tinsel. My mom didn't buy the "Angel Hair" out of preference - the tinsel was unavailable because so much lead was needed for bombs to drop on Vietnam.*
It was only 2 or 3 years until PVC plastic tinsel strips became available, and our trees could be nearly as pretty again.
*The moment Mom told 5-yo me that marks the beginning of my (nearly) life-long anti-war convictions.