Think of this…..Simple shapes of value, different sizes and edges of various softness between them. Lined up side by side, top to bottom, they form the visual image that we perceive as a “thing”.
In the early sections of my teaching curriculum, I teach my students to make an edge chart. They start at the top by making a swatch of dark value on the left and light value on the right. These two values either separate immediately (sharp edge) or gradually, with transitional values in between the two main ones (soft edge). The first set of dark next to light swatches at the top of the chart having the sharpest break or “fence” between them, meaning the most immediate break from dark to light. Then 10 to 15 more sets are made below, getting softer as they go, with a progressively widening band of transitional values (softer edges) in between the two main ones.
In my class I call them fences. I ask my students to paint the fences (edges) first, then grow the different grasses (flat values) on each side. Some fences are sharp like razor wire fencing, while others are more blunt or rounded like split rail fencing, still others are like rock wall fences or hedge rows fences- very wide . Some grasses on either side of the fences are are “Kentucky Bluegrass” (maybe a 30 percent gray), some are “Zoysia grass” (maybe a 70 percent gray)… or if you golf, grass on one side is the rough, the other side possibly the putting surface.
This is just a fun way to help ingrain in the students mind that very different edges exist in the visual world as dividers of visual shapes and should exist, accurately, in their rendering of it.
Endless evidence exists in great paintings both past and present that a wide variety of understood, intentional and widely varied edges make for dynamic and convincing depictions of our world. This applies to any subject matter.
John Singer Sargent made wonderful suggestions, plans and notations of these fences in his preliminary sketches for portraits. An “edge map” of sorts. In one place he’d push hard with a sharp graphite line to indicate an area in his composition where a hard edge and strong contrast would exisist in the final painting. In another area he would indicate a medium soft pencil line that wiggled as it moved along a shape. This would indicate a medium soft brush mark to come, a fence dividing two shapes of value in his eventual rendering displaying medium visual importance. Still other graphite lines are very subtle, hardly perceptable, but still recognizable as shapes that would be an eventual very wide and soft division between two values in his painting. Sargent is but one of many that understoood and utilized this principle and tools to indicate it.
In this way he preplanned and mapped his edges before ever touching his canvas. He could then focus on the luscious brushwork that we all know and admire to convey a particular edge in a particular area. One stroke clean and sharp, another wiggled as he moved along yet another just barely scratching, scumbling a ghost of a division between two areas of value.
I try to start my paintings in this way and encourage all those that I teach to try the same. In this way we all are “aiming for the fences” in trying to “hit one out of the park” on canvas. 😉