I just recently bought a cone of Bottom Line thread for my bobbins. I've been using it while piecing my current project but I got to wondering if I should use it for quilting as well. It's a lighter weight and thinner thread, so I wasn't sure if it's meant to be used in your bobbin while quilting?

Yes it is made for use in the bobbin, to quilts. Alot of long armers use it in their bobbins. I have a few cones, but I like So Fine and I use that in my bobbin on my HQ16, and sometimes will use to top and bottom. There is ALOT of information on the Superior web site under education.

I've quilted several quilts with it as top thread and bobbin - with great results. It's superb for close quilting. The "silver" colour is almost transparent and great for stitch in the ditch too.

It has to be one of my favorite threads. I can not always afford it, since is more expensive than most threads, but it lasts a long time because you can put a lot more on the bobbin and is great to stitch for a long time without stopping to change bobbins. I also use it on the top and bottom for quilting when I want to do microquilting.

ok...here's a dumb question. What's microquilting? I'm still fairly new to the quilting world.

I like using very thin thread for machine quilting, for bobbin and top thread. My favorite is YLI silk thread on the mini cone. It's expensive so I don't use it on utility quilts but I love how it makes my stitches look almost perfect. Sew Fine, FilTec, InvisaFil and Bobbin Line threads are strong enough to use for machine quilting.

Microquilting is when you quilt the lines very close together. Micro stippling is an example. The lines of regular stippling might average perhaps an inch or two apart, whereas the lines of micro stippling might be 1/4-inch apart. Very close quilting like this will make the quilt sandwich very stiff if you use regular thread. If you micro quilt, you need to use a finer thread for good results.

Superior Threads website has a very nice reference chart for thread use.
http://www.superiorthreads.com/page/330/

I've also done some piecing with bottom line in top and bottom. The thread is so thin, pieces press beautifully and go together better because there's not so much thread bulk in the seams.

Thank you for the link, very informative! Apparently Superior Threads does not reccomend piecing with Bottom Line thread due to the high temp iron use that pieces get. I never thought about that. Polyester doesn't stand up to heat very well. I wonder if I should switch back to 100% cotton thread for top and bottom for piecing?