Some 20th-century realists, such as David Hockney, tend to paint a blank wall as, well, blank. By that I mean that they mix up some color and paint that wall a flat tone. No texture, no color variation, just one plain color. If the blank wall has, say, a cast shadow falling on it, they will paint that, but the shadow will also be just one undifferentiated color, just like the light portion of the wall. Skies, tabletops, streets—even skin tones—tend to get the same treatment.
That doesn’t work for me. First of all, it’s not “realistic,” in that human vision (at least as I experience it as a human with functioning vision) never has areas of flat color. If I look at a plain wall, it has constant variations in hue, chroma, and value. I just don’t see any flat color there.
That doesn’t mean the artist can’t paint it flat if that’s the way it looks to him or her, or if that evokes a certain feeling the artist wants to reference. But the big problem with flatness is that it distances me emotionally from the painting. Flat color pushes me away. It says, “there isn’t anything to see here—this space intentionally left blank.” A flat area of color emphasizes the reality that the painting itself is flat. The painting becomes less realist and more abstract, in a way that I find unappealing. Flat paintings are more “modern” (in the sense of being more 20th century), but that’s not a selling point as far as I am concerned. I like simplicity in paintings, but not that kind of simplicity.
By contrast, texture pulls me into the painting. It can be used to create a sense of mystery, as in the subtle darks of a Rembrandt painting. It communicates more about the visual reality that the painter is attempting to lure me into observing. It gives me a reason to spend more time looking, and from the standpoint of a painter, that is never a bad thing.
As a result, I spend lots of time with the “blank” parts of my paintings. I typically use multiple layers and think about how much texture and color variation to apply. Some blank areas get more attention than detail areas. That doesn’t show so much in a photograph of the painting—but that’s just one more reason why the original is better than any reproduction. And that, from the standpoint of a painter, is an excellent thing.