First, take a moment to determine the 'value range and rate of change’ of the gradation to be executed. How light or dark are the values to be? Is it a fast or slow transition from light to dark? Being sure about these factors at the onset will move you one step closer to confident execution.
Next, establish the boundaries for the gradation along with any reference lines that may indicate a major disparity or change in value. Shown here by the line labeled A, this line will serve just as any we would use in our early drawings to indicate a major light and shadow divide. Take special note of this line during this exercise as this labeled boundary will also serve to illustrate the way we use ‘anticipation’ to create some very successful gradations.
In the same manner that we begin to add value within the majority of our tonal-drawing endeavors, here we begin by carefully massing in our darkest value. Even though we have decided to keep our shadow the darkest value possible with our soft charcoal pencil, we will still build it up carefully so as to avoid any adverse effects to the paper’s surface.
For most dry media endeavors, our artists will use a ‘pendulum dynamic’ of application. This means that lighter strokes dispensing materials on the crests of the tooth will precede slightly heavier pressure pass that pushes material from the crests to the troughs. This dynamic tends to preserve the tooth of the paper for a longer period, especially with harder materials, and allows for a more effective layering of materials.
Using very heavy pressure right off the bat will potentially burnish or flatten down a good deal of the paper’s tooth or surface texture. It is this tooth that will allow us to build up multiple layers of charcoal if needed. In some cases, when we know that an area will truly be the darkest dark, we may use heavy pressure right from the ‘get-go’ and establish it rather quickly–but for the purposes of keeping our options open we would recommend the “safer” route here…and this means preserving our paper’s tooth as much as possible.
As value continues to be added and pressure is slowly increased, our application strokes continuously change direction. These variations will keep our values developing evenly and helps to facilitate to a polished finish. As you will see, no blending tools --other than the pencils themselves-- will be used to achieve our rendered result. Varied stroke direction and careful pressure control are all you really need to produce a pristine finish.
A key element for our successful merge of light and dark in this manner is anticipation. Our shadow value is intentionally tapered past the shadow line (still seen by the letter A). This is in anticipation of the white to be added. The tapering of charcoal will mix with the addition of white pastel to create our basic gradation. In this approach, slower, more gradual gradations, will have a longer tapering of early shadow values, while faster rate of change gradations may start shorter… and remember, a crucial component for tapered application is indeed pressure control.
This graphic shows how opaque gradations of value will require tapers to pass the light/dark boundary line in both directions. Many novices will taper far too early, leaving a significant material deficit that often adversely affects the perceived evolution of value. Adequate tapers will avoid this deficit and yield a uniformly opaque result.
White pastel is added next with the same care taken to build up slowly (the pendulum dynamic is highly effective here). Once again, this care to minimize damage to the tooth of the paper gives us much more room to add subsequent layers. Do not forget to continue to vary the direction of your strokes for an even application.
Next, the white pastel is carefully tapered into the previously added charcoal. Pressure is reduced our main light-dark separation, but still tapers a bit beyond it. Again, longer tapers in both directions will yield a slower gradation while shorter ones will yield quicker.
Here are a few close-up images of the above gradation:
At this point, alternating layers of black charcoal and the white pastel refine the gradation. With each application we taper less and less until the major light and dark separation occurs at our predetermined shadow line. We are constantly correcting the gradation’s jumps, skips or inconsistent patches of value with each alternating layer. Continued practice with controlling your pressure will make developing the gradation evenly much easier.
The level of ‘finish’ you are able to achieve will increase with your experience. Another aspect to consider is that the majority of our refinement layers are done with light pressure and large strokes. The finished result should be a successful gradation of light to dark that meets your intended range and rate.
Gradation Block #12 Close-up