My LQS told me if u were sending a quilt top to the Longarm u should press all seams open, but when I actually talked to Renee( the longarm lady ) she said no way, always press to the side, esp if quilting in the ditch.....so I am going to listen to her because she is doing the work and has the skills. Maybe, if u r sending it out, u could talk to ur longarm quilter for answers?