It is truly liberating to get courageous enough to change tension, both upper and lower. Buying a 2nd bobbin case for those of us that are chicken helps this process. So does watching videos on tension, like those of Bob the thread guy from Superior Threads, and even the one for long-armers by Jamie Wallen on Youtube. The 2nd bobbin case does not need to be one with the "pig-tail" or extra tension coil, so is substantially less expensive than the bobbin case that probably came with the machine.

I'm reminiscing about the fabric and thread used to check tension at the dealer...a 50 weight polyester thread on a heavy cotton, folded with 2 or 3 layers, and the top thread is pulled way to the underside during embroidery and satin stitching. How many of us sew like that?

I think your dealer is mistaken. TRY IT!! You may have to tweak your upper tension with different threads, but there is no reason why you can't use bottom line in the bobbin and something else in the top. In fact, it's called BOTTOM LINE because it was made to be used in the bobbin. It's not called TOP AND BOTTOM LINE!

When using different threads in the top and bottom, you just might have to adjust your tensions. This is not a big deal. I have 2 Bernina's and use different threads top and bottom all of the time. I've never had to adjust the bobbin tension, but I do need to thread the bobbin thread through the hole at the end of the little arm on the bobbin case (not sure what it's called) when doing FMQ. Otherwise, I've been able to keep my tension adjustments to the top.

I, too, have used a variety of threads with Bottom Line in the bobbin. I particularly like to free motion quilt with Bottom LIne in the bobbin.

I've also used a variety of threads on top with Bottom line in the bobbin.

While I often use Bottom LIne in the top in my quilts when I want a thin thread (often if I don't have the right color in silk, for instance, but do in Bottomline), I also often use many other thread types with Bottom Line. I use it with 40 wt polyesters, 50 wt cottons, metallics, 100 wt silks, and on and on. I have three Berninas...an 830 LE, a 350, and an old 1230. They love Bottom Line.

I would love to know what thread people use in the top of the machine when they are using Bottomline Thread in the bobbin. My dealer told me I cannot use Bottomline in the bobbin on my Bernina unless I use Bottomline thread in the top. please let me know if you think this is a true statement.