This is a quick 'tutorial' to give you a little insight into how I draw certain materials - Maybe it will give you some ideas! In this particular drawing, we have corduroy (the jacket) and the blouse / undershirt.
Drawing the corduroy jacket is quite a repetitive process for me as I like to build up a lot of tones through making lines, smudging, highlighting and repeating (see below).
I drew a set of lines in the directions of the material; curves around the edges, angles as well as keeping perspective in mind (parallel lines will appear to drift closer together the further away they are). I then muted these lines by smudging with a tissue. Once I was happy that all the lines were where I wanted them to be, I repeated the lines again but filled them in using more of a shading process. This started to give the effect of little ridges. I repeated the smudging and shading process again and then used my Tombow eraser pen to highlight the center of the ridges.
Blouse / Undershirt
The under shirt was a different process, with no lines involved. I started by lightly shading in the the areas that were to be dark (around the neck and tie etc) and smudging over it with a tissue to get the smooth effect. I then highlighted the ridges by erasing lightly with the bar eraser. Once again, this process was repeated until I was happy with how it looked. These are the guidelines I generally follow in regards to a standard material.
- Small rides (or bulges in the material) are generally look lighter and can have a sharper gradation from light to dark (see around tie).
- Bigger, rounder bulges (see the bottom right of under shirt) typicallyhave a more gradual transition from dark to light.
- The more height the ridge has, the more shadow it will produce.
- A softer transition gives the appearance of smoothness.
To practice, find a photo of some material and use it as a reference to get a feel for the tonal values. The image below is a good example!