Originally Posted by
PatriceJ
Do a test sandwich first.
use the same top and back fabrics, and batting, that are in your quilt.
you will probably be fine with a size 14 quilting or embroidery needle, but might need to go up to a 16.
the test will tell you what you need without risking the quilt itself.
I totally agree with this. You need to do a test sandwich first, using the same batting and, if possible, the same fabric as your top. Since you said there's lots of seams, I'd actually piece a block to practice on.