Nap Layout Calculator — Extra Fabric for One-Way Layouts

A common rule of thumb is to add about a quarter of a yard for every yard — roughly +25% — for a "with nap" layout (Sewing.org Napped Fabrics guideline). Flat one-way prints and satin sit at the lower end (around 10–15%), while deep-pile fabrics such as velvet, corduroy and faux fur can need 30–45% extra because every piece must run the same way and the pile direction must match. This calculator graduates the allowance by both garment type and fabric type.

A nap layout means all pattern pieces are placed in the same direction on the fabric. This is essential for fabrics with a nap (like velvet or corduroy), a sheen direction (satin), or a one-way print so the fabric looks consistent across the finished garment.

Stroke the fabric — velvet and corduroy feel smooth in one direction and rough in the other. For satin, tilt the fabric under a light to see the sheen direction. For prints, the motif direction is usually obvious. Cut with the nap running downward for a richer colour.

Not directly, but narrower fabric (90–112cm) already needs more yardage for any layout, and the nap constraint makes efficient piece placement harder. The percentage extra stays similar, but the absolute amount of extra fabric is greater for narrow bolts.