my customers usually bring batting with their quilt tops- unless they are long-distance- the customers who mail me their quilts for quilting send $$ for batting and i provide it.
once in a while i get one in with a batt I HATE! (unfortunately usually a fairfield--not that fairfield doesn't make good batts- they do- but not all batts are good for long-arm quilting!)
if the batt is best suited for hand quilting it may not be so great for long-arm quilting-
some of them are so fragile that just draping it across the frame causes it to pull apart- you deal with holes---i HATE IT...so when someone brings me one like that i let them know i will be replacing it with something (usable)i do not charge them for the replacement batt-since they did bring one- but i use it up some other way--or if they do want it back then they pay for the new one.
ive long-armed all kinds of batts, cotton, poly blends, bamboo, silk, wool...dream green (recycled from bottles)
and have had wonderful outcomes from all of them-except that dog-gone one that pulls apart from it's own weight.