I found out for myself that even a so-called GOOD brand of thread can have a lot of lint. I've posted pictures of the quilt I'm machine quilting with Anita Goodesign software - 80 5" x 5" block + sashing. I've used 2 different threads I already had in my 'collection.' It's A LOT of machine quilting. And a lot of thread.
First, I used Sulky 30 wt Blendables Long-Staple Cotton, because I liked the color variation. I had to stop & clean the fuzz out FREQUENTLY. I can just imagine how much is in places I can't reach. I'm taking my machine to be cleaned as soon as I finish this project - if it doesn't stop working before I finish!
It wasn't the bobbin thread, because that is a polyester, and I've been using it with the other threads I'm going to tell you about.
When I ran out of the Blendables thread, I switched to Signature Trilobal Polyester, a similar variegated to the other one - absolutely no trouble with fuzz. When I ran out of it, the only variegated thread JoAnn's had in the color I want was a Coats Polyester. I went to JoAnn's, because it's only 10 minutes away. I haven't used enough yet to see how much fuzz is building up. I'll notice the first time I change bobbins, and if it's a lot, I'll drive a little farther (30 minutes each way) to my favorite LQS and ask Donna (my semi-local Pfaff dealer) to recommend a thread. I really trust her. She answers questions on the phone - even when I think I'm asking a stupid question. She's SOOO patient, and she 'walks' me through things.
I'd rather spend more $ on thread than have lint gum up my machine where I can't reach to clean it. I have to drive 30 minutes each way to have Donna's husband clean it! But I have to leave it for a few days. Ouch!
Thanks for the tips everyone, Eddie especially for starting this discussion.