For gestural excitement, try to use the biggest brush you have on hand – for the task at hand.
Above is a detail from a quick study I did of an old-school carpenter named Jim sometime late last fall. (click on the image to see an extreme detail.) I spent about three hours on this painting, a one-off. Jim walked into my friend’s studio one night and I didn’t know what I was going to do with him. But he exuded some real character and I wasn’t going to waste the opportunity to capture it.
You can make a good guess at what brushes were used by the strokes you find in this detail. The brushes were were hefty boar-bristle #8 and #10 flats. However, what might be a bit deceptive about the marks in this detail is that sometimes I used the flat tips of those brushes for my pulls, and sometimes I used the sides. And at other times, I used just a corner of the tip. Held at an oblique angle.
But why do this? Isn’t a Flat supposed to be held flat? Wasn’t it designed to leave a squared-off mark? Sure. But if there is one basic rule of thumb to painting expressively then it is to vary the stroke as much as possible. A painting constructed with a single repetitive mark usually ends up being a dull and unexciting experience for the artist and viewer. Even the Impressionists – who were known for laying down short repetitive daubs of broken color – offered lovely variation in their strokes. You just have to look for it.
Here is Jim in full. You’ve already been up close to his eye: