i use lots of serger thread too - i've never had a problem with it. i did have some expensive cotton thread that was old and breaking alot...i donated it to the local boy scout troop...they had all kinds of uses for that thread (and a whole tote of empty spools) so now when i get some that for my use is (garbage) i give it to them...what they do with it works fine...and no, i don't know what they do with it...but the scout master said he would take any and all i wanted to get rid of anytime :)i don;t actually throw hardly anything away...seems like every thing in my sewing room is useful to someone else when i no longer have a use for it... the senior center, the elementary school art department, the pre-school, scouts, 4-H'ers, and many many more are more than happy to receive any of our no-longer-useful items...and they put them to good use! even when i thought it was just garbage not good for anything...i was wrong, they are creative!