I just realized that what you buy in the store called "single fold bias tape" is what I call "double fold" when I make my own, but in fact, pre-packaged double fold has 4 creases in it (or actually 5, if you include the center crease). I haven't bought or used any pre-packaged in so long that I forgot about that. What I was calling single fold is just the strip of fabric pressed in half; I was calling double fold (for which I use the tape maker) when both edges are pressed to the middle. I think that's what you were thinking, also, but I wanted to clarify.