if you 'nest' your seams they do not build up- turn one one way the next the other way- & nest them side by side. alternate rows, so seams are pressed in one direction for one row- the opposite direction for the next row- and nest them as you join them. i've heard of beating seams with a hammer-but doesn't that break down the fibers??? an awful lot of work- to just destroy the integrity of the fabric--(just my thoughts)