When you are first learning to sew many things about ready-made sewing patterns can seem confusing.   For instance, what is this fuss about laying the pattern out according to the nap?

Napped fabrics are those that have texture, pile, or are shiny. The color of napped fabric can appear a different shade when looked at from a different direction.  For this reason napped fabrics must be laid out and cut in one direction.  The napped pattern layout shows all the tops of all the pieces facing in the same direction; a napped pattern layout will take more fabric, so plan accordingly.

How do you tell which way the nap is running?

When you stroke a pile fabric in the direction of the nap it will feel smoother; the color will also be lighter.   Velvet or velveteen fabrics look best if you lay them out with the nap running up; this shows off their richest shade.  On the other hand, suede cloth, corduroy, and deep pile fabric wear best if cut with the nap running down.

It is usually easy to determine the nap of one way designs.  Most have an obvious top and bottom.

Shiny fabrics, like satin, and some knits reflect the light differently from each lengthwise direction.  Just lay them out in the direction you like best.