I am doing a list with synthetic tips which i have "overlooked" (like G10 etc.), and when i have them scraped together, i will test their hardness. So thank's for your suggestion with the linen phenolic.
There are so many cue tips on the market that one can loose the general view. Sometimes i get the impression, that each day is a jump-start for a new tip.
I think, the synthetic tips, i have tested are only the tip of iceberg. Bet, there exist many more.
So, i am thankful for each hint.