Learned something about thread today.
 

Today I've learned that you don't mix your threads. Bet you all already knew that! I was quilting with my Juki/frame and was running low on thread...so, I decided to use some different thread same color (white) in the bobbin & use my better thread in the needle. Well, it was a mess & at first I thought that it was me, because I'm learning to quilt on a frame. Looked at the bobbin thread again & noticed that it is polyester & my needle thread is cotton. Went to the quilt store and bought more thread and the problem is solved. But, I've got a bunch of stitches to take out. I'm going to try to keep the quilt on the frame & roll it back to take out the stitches. Hope that works.

I've changed most of my threads to cotton. I have some like Botton line that I use for the bobbin and doesn't cause any problems.

Thanks for posting. I am a new longarm quilter and have lots to learn. I do better with little bits of info here and there, and this will help me remember to always use the same thread type.

I mix threads..no problem...sometimes you have to adjust the bobbin tension to compensate, but almost everyone mixes threads sooner or later!

I tried everything from adjusting both tensions, changing the speed, rethreading the needle, etc. Maybe my machine is a bit picky.

I dream of a longarm. I recently bought this juki/frame used to learn on and one day I hope to have a bigger set up. Good luck with your longarm and remember to post pictures.

I mix treads also, never had a problem. Some time differant wt. threads. It may just be the machine you have, some you can get by with and some you can't.

Agree maybe your machine is a bit fussy. I have never had any problem mixing threads.

I prefer to use a thinner thread in the bobbin. You get more on it and the quilting doesn't show the boo-boos nearly as much especially when using a solid backing. Did you try adjusting the bobbin tension? Sometimes tightening the top tension a little will help balance the thinner bobbin thread. If I was in the middle of a quilt, though, I probably would not change types of thread on top or bobbin.