A friend who teaches quilting classes ( I haven't had any classes) told me this is from the olden days when quilts were hand quilted and the seams pulled apart if the seams were opened. She stated that now with the machine quilting, it didn't matter and the seams can be pressesd either way - whatever works best because the quilting is stronger. Makes sense to me. :!:

Thank you, Ina, for asking the question. I am a beginner also, and all of these answers gave me more confidence, and I feel that I now have the knowledge to make my seams match. RitaMM