Professional photographers capture the most important and interesting features of a subject. They use framing and lighting and perspective and lens selection to do all that. Some of those creative aspects of a good photograph also come out in a stencil. In particular, when shadows fall just right, those shadows are gold in the stencil maker.
My favorite portrait stencil is a three-tone stencil painted on a white background. That means I paint the mid-tone and dark layers only. You can sometimes reproduce some of the gradient effects of high-quality photographs using different pressure and different coverage while you’re spraying the stencils.
In the video, I observe that the outside ‘rim’ of the subject’s face is darker than the center, so I cover the surface of the mid-tone layer a little more thickly toward the outer edge than at the center. In some cases, you can ‘lose’ an edge of the mid-tone stencil into the white altogether, although the stencil has to be pretty big in order to do this.
With portrait stencils, you want to hit the eyes with the highest coverage for both the mid-tone and dark layers. (So, the mid-tone coverage for the eyes should be almost as dark as the darkest layer.) It’s possible to take this too far, as in the first example the young man has ‘raccoon eyes’ (fixed in second rendering). But you get the point: stronger coverage around the eyes almost always makes the rendering more interesting.
Just like a professional photographer, you can dodge and burn (lighten and darken) areas as you paint. I chose to eliminate the blocky lower edge of the stencil by not painting all the way to the square boundaries of the bottom of the image. I also chose to not block the dark upper boundaries of the dark jacket. Instead, leaving them lighter and softer across the top, as they would be in real life since the shoulders catch the light from above.
Another lesson learned from this rendering: you almost never get it totally right the first time you use the stencil. The raccoon eyes, the extraordinarily dark patch under the chin, would be done differently in a subsequent version.
The images here come from a project in which photographs were taken of the same kids 6.5 years apart.