I will try that, thanks!!!!

check your tension, maybe lengthen your stitch a tad and press and starch the backing fabric. I've done this quilt as you go thing and no puckers so it must be possible... I used fusible batting, only pinned the first strip. If you have spray baste, maybe try that instead of pinning? On something this small, the pins may be causing the puckering? Just a thought!

Starch is a good suggestion. Starch the backing fabric into cardboard so it will behave!

that is what I was going to suggest. Starch it stiff.

Thank you. I have tried all the above, with and without pinning, tension adjusting, etc., alternating sewing directions, but I haven't tried the starching the backing fabric. I will try that next. THank you everyone for all your suggestions, THERE HAS TO BE A WAY

You are quilting along the bias grain of the backing fabric. The bias grain is very prone to stretching.

I avoid this problem by heavily starching my backing fabric before layering a quilt. Starch stabilizes the backing and prevents puckering.

Some people use spray starch, but I prefer my own method -- especially for large pieces of fabric such as quilt backings. I mix a 1:1 solution of Sta-Flo liquid laundry starch and water, lay the fabric out on my kitchen island, "paint" the starch on with a large wall painting brush, toss the fabric in the dryer, and iron with steam.

On the QAYG table runners I have made, I starched the dickens out of the fabric, and I also pressed after each additional strip was added, finger pressing doesn't work well with this technique for me. This kept the back from puckering for me :wink: :D:D:D

Also, make sure you are pressing, not ironing :D

Prism do you put the fabric in the dryer when it is wet?

Yes.

What about using a basting spray on both sides of the fabric before sewing it together