Are you "pressing" or ironing. I know it sounds dumb but it does make a difference. Use steam and "press". 'As for the tearing I tear as far as I can reach before moving my hands. For a border piece that would probably be in at least yard increments. Fabric is not a finite entinty. My husband is a machinest and spends most days cutting up huge pieces of metal. It has to be perfect so that the things made from it fit together properly. The slightest difference in temperture etc. can make the metal smaller or larger. He has even had to transport metal pieces across the shoprin a cooler with dry ice to maintain their size and shape. If metal is impacted by heat and cold etc. how can we expect fabric to maintain it's size and shape when it is so much more pliable.