Originally Posted by dedpete
I am looking for a string that has great durability as well as playability but doesn't hurt my arm. The only string that I have used that has ever hurt my arm was red code. I am wondering if 18 gauge kevlar would be good
If arm pain is an issue stay away
from kevlar/aramids. Some people on here swear that in micro gauges at low tension it is arm friendly, but that is only a vocal few and not the prevailing opinion of experienced players. Either way, if you've had any arm pain in the past it's not worth the risk.
that said, it is about as durable as it gets. I highly doubt that anyone, even tour players, could break it in 3-5 hours of hitting. perhaps that poster had a set that was damaged during stringing. there's a reason why bullet proof vest are made from this material.
tension loss is not as big of a deal with kevlar (compared to polys) because where a poly sometimes feels like the tension fell off a cliff after a few hours and it suddenly goes dead, kevlar plays so dead to begin with that it does not feel meaningfully different after its lost a lot of tension. the change in feel is very gradual and you can play with it basically until it saws through your crosses.