Chele
If your talking about the large spools that are for a serger, thats what I buy, mainly because I free motion quilt and it takes so much thread. They to are to big for my spool on my machine, but they work for me. As the thread gets low on the spool it will on occasion flip off, due to becoming lighter in weight, but as of yet has not caused me much of a pbl. And I might add the faster I go, will cause the spool to flip off, if the spool is low on thread. But in the long run it works for me, considering all the thread I have to use when free motion quilting.