I use the invisible thread for satin stitch applique, yes, even for baby quilts. I also do this so there is very little chance of a baby getting fingers or toes caught in the invisible thread. I pull the thread through to the wrong side and tie it both at the beginning and at the end of that particular section of stitching. I do NOT rely on the machine to tie the threads -- I make sure the thread is tied on the wrong side of the block to which the applique is being attached. I have no problem pressing the blocks either -- just do not use the hot setting on your iron.