When quilting on a machine with frame...do you iron the seams open or to one side?

i do whatever is best for ease and block construction.

some blocks must have their seams pressed open to avoid bulk when joining.

the machine on a frame doesn't have a problem going over seams because it has a hopping foot.

I prefer to have the seams to one side. I think it gives the quilting more strength.
It may be just in my mind.

For the top --- one side and as others suggested. I don't know about it giving "strength", but I do know it keeps your top from having the stitching show.......

If you piece the back, do 1/2" seams and press open. I didn't think that would be so important until I did the last quilt -- the back was pieced with 5 different fabrics and it was a nightmare!!

I iron to the side. One benefit is that if the thread ever breaks and the fabric starts to pull apart, I can't see the batting.