I use Isacord thread to FMQ on my Janome. My machine loves it. I usually use Bottom Line or So Fine in the bobbin with it. In fact, although many people swear by Glide for FMQ, I get better results with Isacord.

I always find it interesting, and amusing, how machines prefer different threads. Don't get me wrong, one of my machines is more finicky than my other 3. It happens to be a computerized machine. I wonder if that has something to do with it?

I would just like to know what it is that makes a certain brand of thread work perfectly fine on a bazillion of the same make/model of machine and not work great on that one machine of the same make/model.

Is it the tension?
Is a gear off by a hairsbreadth?
Is it humidity?
Did a butterfly in Timbuktu flutter it's wings, whereby causing a slight current that created a sand storm that pushed some clouds across the ocean and cause it to rain over the sewing machine factory when that one machine was being made so it suddenly doesn't like certain thread...?

If anyone knows the 'why' behind it, please tell because I'd sure like to know.

I think it was the butterfly. https://cdn.quiltingboard.com/images...es/biggrin.png

You got an amazing bargain- so happy for you!!!