What does this cryptic and mysterious "cut on fold" mean? It's a question asked more than any other and those simple three words confuse and confound beginners to the point they give up. The instruction is not clear, nor is it easy to understand or intuitive, so I'll try to help and explain as best I can. Without knowing the pattern, I'll make a couple assumptions. I assume the front and back of the skirt are the same piece of paper and the piece says cut two on fold. The piece probably looks like one quarter of a skirt.
Begin with your fabric folded across the width. The woven edges (selvage) should meet on the sides and the cut edges should line up at either end. Most fabric comes off the bolt from the store folded like this. Place the pattern piece on the fabric so the edge of the paper with the arrows pointing to the edge of the pattern piece are against the folded edge. Pin the pattern piece down and cut along the waist, side seam and hem edges. DO NOT CUT THE FOLD OF THE FABRIC even through the pattern is worded to sound like you should just that. Don't. The three words are wrong, they lie, they mislead. Now unpin the pattern piece from the fabric you have cut and place the pattern piece on the fabric again, the same way as before and cut the same as before. Cut around the waist edge, the side seam, and the hem. DO NOT CUT THE FOLD OF THE FABRIC even though those three little words are dancing in front of you saying cut the fold and daring you to do so... don't give in, they know not what they say.
Now unfold the pieces of fabric and you will see you have a front and a back of a skirt. Now it's quite obvious. isn't it? The pattern words "cut on fold" are wrong, and they need to be changed to "place pattern piece on fold of fabric, cut around pattern piece and do not cut fold of fabric."Cut one on fold" sound for all the world like the fold of the fabric should be cut, and it shouldn't be cut. This placing on the fold is done when a piece of fabric needs to be absolutely symmetrical, both sides. By cutting the pice from folded fabric you get that perfect symmetry.
This instruction is a pet peeve of mine and i wish the pattern companies would stop saying "cut on fold" because too many people do exactly that.
Hope that helped
Sewing and teaching for a long time and that "cut on fold" instruction needs to be banned.