i was going to add about the painters tape too...masking tape if left on for any length of time leaves a yukky residue on your quilt that sometimes leaves a stain...use painters tape or a paper tape instead. and it is not a good idea to go all in one direction then turn...for the reasons you stated...you need to go in one direction then in the other direction, starting in the center, and working out in each direction, otherwise you will get the bunches you were concerned about.