One of the keys to capturing believable surface textures in any medium is accurate rendering of highlights, shadows, middle tones, and reflected light. . . as well as the edges between them.
Don’t believe me? Take a moment and look at the highlights and shadows on the things around you. See how the edges are affected by the surface texture of the object?
There are three important rules to remember when drawing the variations of light and shadow on any object:
1. The duller (or coarser) the object’s surface, the softer the edge of the highlight will be.
2. The duller or coarser the object’s surface, the more gradual the shift from highlight to middle tone and from shadow to reflected light.
3. The duller or coarser the object’s surface, the darker in value the highlight will generally be.
If you want to draw something with a dull or coarse surface, make the edges of the highlight soft, make the shift from highlight to middle tones smooth and gradual, and don’t make the highlight too bright.
There are exceptions, of course. Any surface under an extremely bright light will have a brighter highlight and deeper shadows than the same surface under natural light. But even so, you will do well to observe the rules in drawing different types of surfaces.
Let’s take a look at three examples of objects with coarse or dull surfaces. Let’s start with coarse:
1. Stone globe
This is an old-fashioned hitching post for horses. The town where I live was originally a cow town so this kind of architectural feature is quite common. It’s made of stone and cement.
The light source is from the left and very low, since it was late evening when I took the picture. The highlight (#1) is low on the left side of the globe. Notice it isn’t very well defined.
The rough surface causes light to strike the stone to varying degrees all over the lighted side of the globe. That’s because the “high points” in the stone catch light no matter where they are except for those on the shadowed side.
In the shadows, the “high points” may be lightened by reflected light. They will affect the overall darkness of the shadow, even you can’t see individual specks of reflected light.
It also means that those same “high points” have shadowed sides, too. So highlight and shadow are mixed together in such a fashion that there is no clear line between highlight and middle tones.
The edge between middle tone and shadow (#2) is the most clearly defined edge on the object because it marks the place where the surface of the globe begins curving away from the light. It relies less on surface texture than the other edges do, so it’s the most easily seen. This holds true no matter what the surface of the object is.
Reflected light (#3) is soft-edged, just like the highlights. Notice the difference between the reflected light on the stone globe and the reflected light on the iron ring on top. The iron ring has a smoother surface than the stone globe, so the edge between reflected light and shadow are a little bit sharper than the edge between reflected light and shadow on the stone globe.
2. Red tomato
At first glance, the surface of this cherry tomato looks smooth. But take another look, especially where the middle tone shades into shadow. . . the tomato has tiny hairs on it and if you look closely at the highlight, you’ll see it also has pores similar to human skin.
These two features mean that while the edges between highlight and middle tone and between shadow and reflected light will be sharper than on the stone globe, they will not be as crisp and clean as the edges on a totally smooth surface.
The highlight (#1), for example, is well defined and has a definite size and shape, but the edges are mottled by the pores in the tomato’s skin.
The same applies to the reflected light (#3). Very soft edges blend into the shadow on the right side of the tomato and into the middle tones near the bottom.
The shadow (#2) is most clearly defined at the top, where there is very little reflected light and where it is opposite the highlight.
Now take a look at the white surface on which the tomato sits. Under the lighted side of the tomato is an area tinted red by the sunlight bouncing off the surface of the tomato and onto the paper. This, too, is reflected light. But it’s light reflected off the tomato onto the paper. Light is also reflected off the paper and onto the tomato. The overall effect is a somewhat softened edge between the tomato and the paper.
In the shadow cast by the tomato, there is also reflected light. Because the light bouncing off the tomato and onto the paper is less intense, the reflected light is also less intense. Still, you can see the cast shadow is tinged red.
3. Green apple
Finally, let’s look at an apple.
The light source is to the right and slightly elevated in this illustration, so the highlight (#1) appears on the upper right portion of the apple. Because of the smooth skin (no hairs or pores), the highlight is fairly well defined. Because the surface of the skin is not glossy, the edges of the highlight are blurred. But they have a distinct shape and size.
The gradations between highlight and middle tone is subtle and smooth, but much narrower than what we saw on the stone globe.
Once again, the edge between middle tones and the shadow (#2) is the best defined edge because of the curve of the apple from light into shadow.
But look at the reflected light (#3). The edges between reflected light and shadow is soft, but it’s still sharper than the edges around the highlight. There is also more evidence of reflected light on the apple and on the surface on which it sits. The smoother or more shiny an object is, the more clear the reflected light.
Creating the proper surface texture is one of the most important aspects to accurately replicating real life objects. The more you know about surface texture (and how it reflects light) the better you’ll do at re-creating it on paper. Good luck, and happy drawing!
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