Fabric cutting details - cutting on "fold"

If a pattern piece has a “place on the fold” notice, that means to place the pattern piece perpendicular against the fold of the fabric. Pin the pattern exactly along the fold and only on the side of the pattern piece then cut the pattern piece out and when its cut, the pattern piece is now double and has a left and right side. This is used for pattern pieces that should not have a seam , think, a front panel of a dress. This just looks better as one big piece instead of 2 pieces sewn together.