I usually use the same thread in the bobbin that I use on top. I fill several bobbins before I start quilting so I don't have to rethread the machine every time I change the bobbin.
Linda OH

I use the same thread in the bobbin as on the top, but I've run out and had to stop and wind another bobbin. Like Linda, I try to remember to do enough before I start so I don't have to do that. When I'm FMQ'ing I almost always start with a full bobbin so I don't have to break the rhythm of sewing just to add a new bobbin.

Kate

My machine is fussy and it likes mainly King Tut on top (Superior Threads) and Bottomline on bottom, a fine poly that makes the bobbin take about twice as much thread it seems. I wind a bunch of bobbins ahead of time to cover a whole quilt or close to it. I'm currenty playing with a couple of others and might broaden my horizons if I can pin down the proper tension.

toolgranny - have you seen the Towa gauge for bobbin tension?
I am thinking of getting one to help with the changes in bobbin threads. Superior threads has a good price on it.
You need to know if your bobbin is a size "M" of "L".

Here is a link that might be useful: Towa

Another one who uses the same on top as in the bobbin.

Teresa

I must use King Tut or my machine really has a tantrum. I can get away with Bottom Line in the bobbin, but it really likes the King Tut top and bottom.

I bought a TOWA gauge, and still had trouble with my tension. The new representative for my machine told me to throw it over my left shoulder and hope it went out the window. I have used it to get the tension "close", but still have to fine tune before every quilt.

beverly

I usually use the same top and bottom.

I'm curious why someone would be startled or upset by running out...most quilts take several or many bobbins to complete the quilting.

On the full-size bed quilt I am quilting now, using prewound bobbins, I'm about half done and I've used 3 bobbins. I expect to use 5 more.

What is her expectation? Bobbins are the size they are - they only hold so much thread.

I usually use bottom line because the bobbins last longer than regular cotton thread. Although I do expect to have to change the bobbin often, it is more annoying with a drop in bobbin like I have as opposed to one of the front loading bobbin style machines.

Have never see the Towa before. But, I have no trouble with bobbin tension at all. I never change it.

Upper tension is the only one I fiddle with and it is set differently for FMQ, FMQ with invisible thread, and for piecing. I still can't get an upper tension set right on my machine to take a 12 weight thread but someday I'll figure it out.

I'm curious to know what kind of machine some of you have that you have to use King Tut thread. If you don't mind telling.

I almost never mess with the tension on my machine, except for when I'm FMQ or if I'm using a stitch the recommends a different tension setting. I don't believe I've ever adjusted the bobbin tension. Do some machines not require that or have I been living in a fog about this?

Kate

Kate, my dear, you aren't living in a fog - just a mist, LOL.

Most machines have enough top tension adjustment to cope with almost anything, so you wouldn't have to adjust the bobbin tension.

I sew everything from upholstery fabrics with heavy-duty nylon upholstery thread to delicate cotton lawn and batiste with a 60 weight thread. I piece with balanced tension, but embroider with far more tension on the bobbin (to pull the top thread to the back).
I keep two bobbin cases marked for embroidery and general sewing.

Thanks Mary!

I use the same thread for the top and the bottom too. I just forget to have the extra bobbins ready.
darlene