I have 40 year old cues that have ALOT of use on them, some with 5 worn out shafts, and the linen is better than new, it is smooth and has alot of oil from the players hands, infact properly cared for linen used linen is better than new, the patina it gets looks good, its not bright and shiny, its the hardcore player look and feels better.
However I do have some cues that have low quality linen and it does seperate(the weave isnt good) and it gets rough, its shit and have it replaced. The best linen you can buy anywhere is Blue Mountain-if its put on by a good cue maker you never have to worry about it. If you have friends or get lucky Cortland is better they stopped making it something like 30 years ago, but on a spool thats been stored right it looks brand new, I have had a couple cues refinished with it but they are big dollar cues, IMO the best linen ever is Penn which again they stopped making 25-30 years ago i really dont know-but its my favorite and super hard to find-only a friend will give it up and on the right cue, meaning a old cue that would have had it when it was made like a Bushka, the cue i'm currently playing with was just refinished an dwraed with it, I have put about 30 hours on it and its changing colors and feels better every day,
There is some fake Cortland floating around for sale at around $1/Ft. and it sucks, the white and green kinda seperates and gets rough, It looks like cortland on the spool but when its put on it still looks good after a while it gets fuzzy the green strands come up.