I don't think that most people use a different bobbin weight thread, but many do. I like to use Bottomline on top and in the bobbin. Use whatever works for you and your machine.

I'm using up my 60 weight Mettler thread. I used to do a lot of hand applique but can't anymore so now it is my bobbin thread. I've run through about six spools now and zero problems with whatever I'm using on top.

Sometimes, the machine doesn't like a different thread weight in the bobbin.

A big thank you to everyone who contributed to this thread. I really appreciate your input, and I learned a lot. I am going to try a different weight in my Juki HZL 600 sewing machine and see how I like it. Thanks again!
LaDonna

for quilting on my LA I use either a 40 or 50 wt on the top and 50 wt So Fine on the bobbin. On my embroidery machine I use bobbin thread. So this leads me to a question for the Long Arm users out there. Recently someone gave me over 50 spools of 12 wt cotton thread. It seems very thick to me. Has anyone tried to use thread that thick on your Long Arm machine? And if you did what wt bottom thread would you use. If it can't be used on a Long Arm what would I do with that many spools of 12 wt thread? My guess is that it is way too heavy for Long Arm machines. I hate waste and would love to use this if possible.

I use 60 or higher weight thread for bobbins when piecing. I recently started using 80 and 100 wt for top and bottom. My seams have less bulk and no fold over waste.

LaDonna - I'd love to hear back how it works out. I have a new Juki DX5 and am thinking about experimenting with thread types, thread weights.