Welcome to the Quilting Board!
I use their Masterpiece thread for piecing an top and bobbin. And I use Bottom Line in my bobbins on my long arm and in both when doing SID.
APQS Millenium Longarm with Intelliquilter
I received my DVD and viewed it today. It is really SUPERIOR information. Bob defines the uses of each weight and why. He also explains why topstitch titanium coated is a superior needle. I have used them and agree. They last much longer and are well worth the $1 extra price for 4. They also will bend instead of breaking which keeps them from going into your machine if you have a mishap.
I use Bottom Line in bobbin when piecing, in bobbin in Longarm and even as a top thread in both when I want to use a finer thread. It has never MELTED when I use a hot iron. I even mix the thread sizes & types of thread in my machine, but always use Bottom Line. I have even used Superiors "So Fine" in the bobbin and it works great too!
I really hate to sound dumb, but when you say bottom line thread, are you referring to the prewound bobbins?
I use it in my bobbin for FMQ. I just blends into the background fabric so beautifully.
I use it with King Tut on the top for quilting on my longarm.
Beth in Maryland
I just pushed my like button for this comment. I, too, have been sewing since the 70s and mixing top and bottom threads with no problems with wear and tear - only problem I ever had was using 100 % cotton thread on top and bottom and the quilt is giving way in places after 8 years of use.
A bed without a quilt is like the night sky without stars.