What size needles do you guys piece with? Does it make a different in your 1/4" seam allowance?

TIA

yes the needle size can make a slight difference. Nothing larger than an 80 preferably a 70

I use a 90/14 for piecing and top stitching.
a 75/90 for machine quilting,

75/90 ?

A quilt teacher one time suggested that I use a size 70 Sharp needle, and I've been using it ever since (haven't been quilting for long though) for piecing. It is especially nice for batiks, IMHO.

I ususlly use a 80/12.

It also depends on your choice of thread. Star thread is a little thicker & Bernina lady said to always use a 14/90 needle with it. Aurfill is so fine (and beautiful !) I use a 12/80 with that. cotton covered poly sometimes requires a 14 needle also. and batiks require a change of needle more often so they are sharp. I think there are a couple of internet sites that really explain needles, scarf, etc.

If I piece with Wonderfil Decobob then I use 60/8 otherwise 80/12 or 75/11