Drawing Fundamentals: Modeling Planes

20 Oct 2009

Objects look convincing when a draftsman models the form correctly. Here, we take it step by step to ensure accuracy and a solid foundation.

by Jon deMartin

Every artist wants to master the modeling of form, using value to create a third dimension in a drawing, so let’s take a look at this fundamental task. It’s a big subject, so we’ll tackle simple concepts first. Let’s begin with modeling the most basic geometric solid—the cube. The cube’s planar surfaces are easy to draw and model because they’re clear and unambiguous—cubes don’t have confusing surface irregularities or changes of local color or texture. Nature’s surfaces are generally curved, but manmade objects are often flat, as in walls, tabletops, and buildings. Plus, light and shadow are more discernible on a cube than on a curved surface.

Noted teacher and illustrator Frank Reilly once stated, “What you will learn on a simple form like a cube or sphere can be applied to a head, figure, or landscape. It will help you see the three-dimensional reasoning of nature. It will help you draw from memory and your purely creative attempts. Values relative to light and shade must be understood as a mirroring of nature before they can be seen as a personal explanation of nature. They must be clearly understood, first and last, by the observer.”

It’s advisable to practice making flat values before graded ones. A flat-value mass is produced by drawing even strokes parallel and touching one another to create a flat and even mass. Dark values are made by increasing pressure, and light values by decreasing pressure. Do not smudge graphite—shaded areas that are smudged have a shiny appearance. Try to avoid haphazard and uneven pressure on successive strokes when creating a graded area.

Illustration 1
Three simple swatches of value—light, middle, and dark tones.

Illustration 1 shows three swatches of value—light, middle, and dark tones. Try to reproduce these flat values, then move on to tackle a value scale. Illustration 2 shows a value scale divided into seven gradations between black and white. The objective is to create a scale from the darkest dark up to the white of the paper and make the gradations as even as possible. Lightly pencil in nine equidistant spaces an inch apart, and number them underneath from left to right. Value No. 1 is black, on the far left, with values lightening up to No. 9, the white of the paper. The value scale in this illustration was made with a soft pencil for the darker values, a medium pencil for the middle values, and a hard pencil for the light values. There are several ways of determining if the values are graded evenly. The values should graduate smoothly without obvious jumps. The contrast at edges should appear the same throughout the scale. When in doubt, isolate any three consecutive values and make sure the value in the middle is not leaning more to one adjacent value or the other. Keep in mind that the artist’s value scale is much narrower than what one sees in nature, because the white of the paper is nowhere near as bright as the sun, nor is black pencil as dark as the inside of a black velvet box.

Illustration 2
A value scale with seven gradations, with No. 1 representing the darkest black produced by a
graphite pencil and No. 9 representing the white of the paper, plus seven gradations in between.

Before shading, a draftsman must be certain that the object’s outlines are drawn correctly and that the linear perspective in the composition is accurate. Once you solve the proportion of the object’s shape and its shadow shapes in relation to the lights, you can free your mind to focus on the modeling (shading).

To practice, I recommend getting a white or light-gray cube with smooth surfaces, no smaller than three or four inches high. Illuminate the cube using a single light source, natural or artificial, from above left with one side of the cube completely in shadow. The ground underneath the cube should be neutral middle to dark gray and should not have a shiny surface. Ideally, a neutral middle-gray background can be placed at a relatively short distance behind the object.

Next, prepare an outline of the contour lines and the edges of the major planes. Keep your lines as light as possible so that they don’t interfere with the values you’ll be modeling. If they are too dark, lighten the lines with a kneaded eraser until they are just a guide for the areas to be shaded. After drawing the outline that bounds the form’s shape, draw the shadow line that divides the overall light from the overall shadow. First mass in the shadow with a value lighter than what you see on the cube—this initial stage is only a preparatory phase for modeling, and your light touch enables you to make corrections before pushing the drawing toward finish.

By using your value scale to help determine the relationship of your lightest light to the darkest dark, you can relate all your values in between. Never take for granted that the values you observe in nature will fall into one of the squares on your value scale. The value scale is designed only to give you a reference point so that you can make better value comparisons. While drawing, continually compare your values in the light to your shadows. Put in your shadows first, and gradually build up the values in flat areas as the drawing develops.


Illustration 3
Changing the vantage point of the viewer allows two planes of the cube to show,
as demonstrated in the second row.

You may notice that the portion of the shadow plane that is nearest the light will look darker than the other areas of the same shadow. This is called the law of contrast in Michel Eugène Chevreul’s 19th-century book The Principles of Harmony and Contrast of Colour and Their Applications to the Arts. He wrote, “The shadows on objects are stronger nearest the eye, and they decrease in strength and intensity in proportion to their distance.” This is the first rule of aerial perspective, which can apply to a local condition as well. This can be observed on the illustration of the value scale where the darkest part of each value appears to be at the edge where it meets the lighter value. In other words, the contrast looks greater where the edges meet.

Illustration 4
Here the vantage point is seeing the edge of two planes of the cube.
In the second row, the vantage point is from below.

Practice drawing cubes in different perspectives under the same light condition to explore how the changes of planes dramatically affect the values. Illustrations 3, 4, and 5 show six rows of cubes, rendered in both line and value, from different vantage points. The cubes on the left are drawn with just lines but read volumetrically because they reveal the interior plane line divisions. The cubes on the right read volumetrically because of their value relationships. Remember, in modeling form, plane and value are synonymous (or interrelated). The first row of Illustration 3 shows only one plane and value because the eye is looking directly at the cube’s center. In the second row, the eye is looking from above, showing two planes: top and front.

Illustration 5
Three planes are visible from this vantage point: top, front, and side right. This is the most
challenging of views—and the one most similar to the orientation of the human head.

In Illustration 4 the first row shows two planes meeting at the corners. The second row is the reverse of the second row in Illustration 3; the eye is now looking from below, showing two planes: bottom and front. Illustration 5 shows three planes: top, front, and side right. The cube in the bottom row is tipped, tilted, and turned, vanishing to a false horizon. This is the most challenging of all views, and it’s similar to what a draftsman faces when depicting a human head. All the other cubes in these illustrations are vanishing to a true horizon. The schematic in Illustration 6 shows the different plane changes.

Illustration 7
by Jon deMartin, graphite, 18 x 12.
A front view of the Cube Man, based on a
sculpture by Eliot Goldfinger.

The ability to identify planes is crucial to modeling form. The figures of the Cube Man in Illustrations 7, 8, and 9 clearly show how plane changes impact values. In Illustration 7, the front view, the rectangular block that is the ribcage is light because it’s a top plane, and the pelvis is darker because it’s an under plane. To reinforce this concept of plane directions, the artist should observe the pose from different views. For instance, Illustration 8 shows the side view drawn in line and clearly indicates the planes’ directions. Notice that in the back view in Illustration 9, the ribcage is darker because it’s going under, and the pelvis is lighter because it’s a top plane—the reverse of the front view in Illustration 7.

Illustration 8
by Jon deMartin, graphite, 18 x 12.
A side view of the Cube Man.
Illustration 9
by Jon deMartin, graphite, 18 x 12.
The back view of the Cube Man. Notice how the
ribcage is darker because it’s going under, and
the pelvis is lighter because it’s a top plane—
the reverse of the front view in Illustration 7.

Up to this point we’ve been talking about values that run top to bottom. In the front view in Illustration 7, you can also see plane changes running from side to side. The front plane of the right thigh is facing the viewer, and the left is rotated outward, becoming a side-right plane. Notice how planes that go to the side darken. (See Illustration 6.)

Illustration 6
The plane changes created by this vantage point.

Drawing simple objects enables an artist to master the basics. By taking baby steps toward what nature shows us, we can build on a sure and solid foundation that will help us become better artists, allowing us to express our visions of the visual world.

 

Materials For Modeling With Values

A graphite pencil is the simplest, most direct, and most valuable of all art tools. It’s an excellent tool for both drawing lines and filling in shaded areas. It’s basically a line medium rather than a broad area or planar medium, and it can be used sketchily or more carefully. However, if a graphite pencil is used too heavily it will produce a shiny appearance in one’s artwork, and it will be susceptible to smudging. Hard pencils tend to break if pressed too heavily in an effort to produce a dark line. Dark lines and shadings instead should be drawn with soft pencils, which do not require great pressure. Use a sharp pencil point. In terms of surface, finer-grained paper lends itself better to graphite; rough papers produce a coarse, grainy look.

For sharpening pencils I prefer a single-edge razor blade, which I use to shave away the wood around the pencil point. I slowly rotate the pencil between my fingers using long shaving strokes so that my pencil has a long, sharp point. This way my lines can be crisp and last a long time before I have to resharpen.

Charcoal or carbon pencils can be preferable to graphite pencils because they don’t leave a sheen, and they can produce darker darks than graphite. The drawback is that they’re less controllable, but this can be overcome with practice.

A kneaded eraser is perhaps the best eraser to use when working with graphite or charcoal. It can be shaped to a point to reach small areas without affecting the rest of the drawing, and it will remove pencil marks without marring the surface of the paper.


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Comments

on 8 Sep 2011 2:56 PM

Check out what's featured in the Fall 2009 issue of Drawing magazine.

on 15 Aug 2012 9:17 AM

Hi Brian,

Excellent info on planes and their values. I think we are missing illustration #6.