Originally Posted by MadQuilter

I generally do not press the seams open because I do mosttly SID (stitch in the ditch) quilting. Because the quilting line runs down the seam, an open seam would be weakened.

However, there are times when many seams converge on a center, I may decide to press them open. So your question cannot be answered by a simple rule.

I try to figure out the assembly pattern early on so I can press the seams on any subcomponents so they nest when assembled. I practiced the nesting principle on a standard 4-patch and 9-patch.

When I have the blocks sewn into rows, I also follow the nesting principle. This means I press the first row to one side and the next row to the opposite side. That way, when I align the rows they will nest and I can pin and sew a clean seam.

To be truthfull, sometimes the seams flip and the back does not look as clean as I would like...but that's life.