That is my comment as well when working on a domestic sewing machine
Congrats on completing your top
Happy quilting 👍

My bit of experience tells me that you might have that stiffness for all the reasons you stated but it shouldn't be a problem if you wash the quilt when you are done binding it.

As far as the quilt going off square. This will happen and I never square up a quilt until after it is quilted. If you like to baste the edge before you start quilting, I would remove it in sections as I worked to the edge of the quilt just like removing basting stitches so the fabric can move out from the center. Even with basting the batting will want to shift a bit as it is worked.

one of my tricks is to make any borders an inch or two wider than What I want it to finish at and then I have enough to trim and square up at the of quilting.

Someone told me to sew around the perimeter. I thought you were supposed to (along with stitch in the ditch top to bottom and side to side, which I did not do).

I have another one to sandwich today, so I have another chance to learn something else. The one I will sandwich today had mitered multiple borders. Now, I know why you can't just make it look right. I had to re-do 3 out of the 4 corners.

This is good however. I have the fabric for a panel that has 5 or 6 borders that are mitered, so my learning experience will stand me in good stead.

Thanks for your help.

bkay

Years ago I saw a video of making multiple mitered borders where she put all the borders together before attaching any of them to the quilt itself. Might be worth looking for. Good luck!

I don’t like to sew around the perimeter first. At most I might use safety pins to keep the edges from separating and remove the pins as I go. I want the edges to be loose so any excess fabric isn’t trapped there.No chance of a big pucker at the edge that way. I don’t think perimeter sewing does anything to keep a quilt square.

Old Fashioned Me, again, but I pin and then baste, from the center out, then quilt from the center out, and I have never had a pucker or fold in the backing.

Make sure your needle is the correct size for the thread. I always start from the middle and work my way to the edges. Use a walking foot. Do not sew around the edges until you are done, the quilt stretches a bit, even when pinned. I sew a big + through the quilt, that way the quilt is divided into 4 parts. Sew up one side and then go the opposite way. You can do a continuous stitch , up and down and back and forth, then cross way.