Take a look at these two swatches of corduroy. Both are on the right side. What do you think is the difference?
The answer? The swatch on the right, which appears deeper in colour, is upside down. The appearance is dependant on how the light hits the direction of the nap. The piece on the left has a pearly, whitish sheen which the eye would pick as you look down on the garment. Most corduroy garments are sewn in this direction.
My tutor once told me she makes all her corduroy skirts on the reverse nap (i.e. so that if you run your hands down your hips, you go against the nap); this is to gain that darker, velvety shade. There is a disadvantage; the nap picks up fluff and dust which will show up against the dark fabric so you have to regularly lint-roll. This is more of a problem with black than with other shades.
What therefore puzzles is me is the apparent success of the Cordarounds: a company which specializes in garments made with the corduroy turned on its side. I’ve made sleeve cuffs and a waistband with cord at crossgrain (on this dress) and the light made one side appear darker than the other. What do you think?