when using cotton thread with cotton fabric I would try a larger needle

I thought cross wound thread went on the horizontal spool pin and straight wound thread went on the vertical? Have I got it muddled up?

What machine do you have? Is this your home machine, or a machine on a frame (home or one meant for quilting?)... hard to help without knowing this. Home machine...Try loosening the tension a little...and as other suggest...use a slightly larger needle & even a slightly larger stitch length. If you are using a darning/embroidery foot...with feed dogs down...slow down. My little Brother machine lets me slow how fast the machine stitches...and that let me slow down a lot. Really helps with thread breaking. If you don't have that... try to get used to not press to hard on the foot pedal.

On a longarm machine (or any machine on a frame really). Loosen the bobbin & top tension)..here is an excellent video by Jamie Wallen:

https://www.youtube.com/watch?v=Q1mRhcquZTM
Taking the Stress out of Tension

I hope this helps some.
Marge
TL18LS (2009)
Qbot V3

Even a new needle can have a burr. Happened to me.

[QUOTE=bjchad;7393119]Check to see if your thread is hanging up somewhere. If the spool has a notch for tucking in the loose end, make sure that the thread isn't coming off that end of the spool.QUOTE]

I was going to suggest that about the notch on the spool. That has happened to me several times. Now I know to thread my machine with that notch is facing opposite of where the thread comes off.

You might also just take the thread & see how easily it hand breaks. Just take it & try to break it by hand. If it breaks fairly easily it might be old thread that is deteriorating.

If you haven't watched the Superior Threads tension video, then I'd suggest you do. I was agog at how loose the tension was he suggested - opened my eyes, I can tell you!

Gah, it was all going so well for a while - until I worked on the middle of the quilt again (I'd worked the very centre, where I had all the initial problems, then worked my out the edge, where I thought I had it sussed, but now I have gone back to the middle to work out to the other side...)

My spools don't have notches on, so I know it is not that.

I'm going quite slowly (DSM, feed dogs down, quilting foot), and I'm fairly confident the tension is correct - the threads seem to be meeting in the middle and don't seem too tight.

But, the thread (Gutermann) is really easy to break by hand, both reels in their different colours. I mean really easy to break - but I only bought it last month. I don't have any other variagated cotton thread (or indeed plain cotton) to compare it to - I've previously only used the Gutermann sew all poly thread.

I have ordered some larger (14) needles online (How I wish I had a wonderful LQS nearby!!).

Thank you all for your expertise!!

This may seem weird but try leaving your feed dogs up. My machine doesn't like having the feed dogs down and I get frequent thread breaks when I stitch that way. Maybe your machine is picky in the same way.

Sometimes cotton thread will break when it's older and dry. That can happen when sitting on a shelf in a shop. Try putting the thread in your freezer for a day or so, or set it outside where it can absorb some moisture. I've only read about these and haven't had to try them myself, but they won't cost anything but time to try.

Found this:
http://www.quiltingboard.com/main-f1...k-t185067.html
The THEORY is that freezing adds moisture and/or contracts and therefore "conditions" the thread. Who knows? The evidence is that it has worked.