Nap

Nap is a raised surface on a fabric, made of fibres or loops that lie in one direction. Run your hand over velvet one way and it feels smooth; run it the other way and it feels rough and looks different. Because the surface fibres reflect light differently depending on which way they point, a napped fabric looks lighter from one direction and darker from the other.

Fabrics with a nap include:

• Pile fabrics: velvet, velveteen, corduroy, faux fur, towelling.
• Brushed fabrics: wool and cotton flannel, brushed cotton, fleece, melton. See Wool Flannel.
• Fabrics with a directional sheen: satin and some sateens and knits, which aren't strictly napped but behave the same way.

Pattern envelopes also use "with nap" for one-way prints, where the design has an up and a down, such as flowers that all grow upward. The layout rules are the same.

Finding the direction

Stroke the fabric along its length. The smooth direction is "with the nap" or "nap down"; the rough direction is "against the nap" or "nap up". Then fold a corner over and look at the two surfaces side by side in good light. If they look different shades, you need a one-way layout.

Velvet looks richer and deeper with the nap running up, so many sewists cut it that way. Fabrics cut nap down feel smoother and tend to wear better. Either is fine, as long as every piece goes the same way.

Laying out with nap

In a with-nap layout, every pattern piece points in the same direction along the fabric, top of each piece toward the same end. Pieces can't be turned upside down to nest together, so the layout uses more fabric. Pattern envelopes list separate fabric amounts "with nap" and "without nap". If yours doesn't, allow about 10% extra. The Fabric Width Converter has a with-nap option.

Mark the direction on the wrong side of the fabric with chalk arrows before laying out, and check each piece before cutting. A single piece cut the wrong way, such as one sleeve, shows clearly as a different shade.

Sewing napped fabrics

• Layers creep. Pile fabrics slide against each other under the presser foot. Use a walking foot, baste or pin closely, and sew in the direction of the nap where possible.
• Trim pile out of the seam allowances on thick fabrics such as velvet and fur, to reduce bulk.
• Expect fluff. Cutting releases fibres. Clean the machine more often.

Pressing

Never press napped fabric flat from the right side, because it crushes the pile and leaves shiny marks. Press from the wrong side, face down on a needle board, a velvet board, a thick towel or a spare piece of the same fabric, and use steam with very little pressure. On brushed wools, use a press cloth. See Pressing.