When Shar Jorgensen was on TV she taught to open every seam, I had been taught press to the dark so it was difficult at first but then it was quite easy if I remember correctly she used her fingernail to open the seam. So when I am doing something that requires open seams that is what I do then use a wooden iron. I actually made 2 queen size quilts that way with no problems. BTW definitely using a scant quarter inch!