What brand of thread do you use when making blocks with white thread? I tried using Dual Duty white all purpose and it pulls up from the bottom bobbin If I use a different color in the top it still pulls up tightly. I also have adjusted the tension and it doesn't help. I have been using light brown for both top and bottom thread and no problems at all and it is Dual Duty also.

I prefer gutermann thread. It seems to leave less fibers in my machine.

A thread I use is Essentials from Connecting Threads if I want cotton. Superior Threads also carries marvelous threads in cotton and poly. The last spool of Dual Duty I bought was really poor and I broke threads every six inches. It may have just been a bad spool, but I won't be buying any more.

Have you adjusted the bobbin tension? It should feel like half as much resistance as the top tension. That usually works for me.

I don't know for sure but I wouldn't think the color of thread would make any difference but if I'm wrong someone with more knowledge about it will correct me.

As to brand, I have always used Gutermann thread up until yesterday when I started using Connecting Threads. Time will tell if it's ok. A quilting instructor once told me that Gutermann was the best and I never had any problems with it, but I've heard many other brands mentioned on here.

I like Guterman. My vintage machine doesn't hold much on the bobbin and I can get a lot more thread on a bobbin with G than DD. I have always liked DD, but my LQS said it has changed and is coming off the spool twisting now. I am still buying it and haven't noticed a problem with my other machine. I am interested in a poly from Bottom Line, but haven't ordered yet. I am the rare person who doesn't care for Connecting Threads cotton. It's very linty and it breaks easily when I have to remove any stitches.

Color does make a difference. I've never noticed anything with white, but black DD is weaker.

I use Connecting Threads thread with no problems.

I've switched over to Aurafil thread, especially for the bobbin but on the top as well. I really like it!

I don't use the coast and clarks.
Have been using the Connecting threads. It's a good thread but I get more lint with it. Sometimes I use the Gutermann

My machines seem happy with whatever thread I throw at them. I do have a cone of super cheap black that is linty beyond belief. I may not use it again even though the machine sews fine with it.

I have noticed that sometimes the coats and clark white thread seems finer than the colored thread - I wonder if that might cause the problem?