Knife pleats and box pleats differ in how the fabric is folded and how the pleats are arranged across the back of the kilt, affecting both appearance and structure. Knife pleats are formed by folding the fabric in one consistent direction, creating a series of overlapping pleats that lie flat and produce a smooth, continuous flow, which is the standard in traditional kilts. Box pleats, by contrast, are created by folding fabric in alternating directions so that two folds face outward from a central point, forming wider, more pronounced pleats that create a more structured and segmented look. While knife pleats are most common in traditional construction, box pleats are more often found in modern or utility kilts, where a different aesthetic or function is desired.