Glass

"Bottle," oil on panel, 4x6, 2011

Most beginning artists are sorely vexed by glass objects. Glass is a difficult subject because of its transparency or translucency. A beginner trying to draw or paint a glass object almost invariably tries to paint the glass itself, but drawing or painting glass actually requires us to see what the transparent glass does to distort objects behind it and to reflect lights that fall upon it. In short, it's not the glass we paint, instead we paint objects as the glass affects them--distortion, magnification or shrinking.

In the examples here, done on small panels with a general thirty minute time limit, my goal was to study the way the bottle, its liquid contents, and the outside light interacted. As I painted I was mindful too of compositional issues and the overall value pattern. The bottle actually sat on a stainless steel table and magnified light by bouncing it upward. The sun was weakly reflected on the shoulder of the bottle, and that light was warmer, more yellow, than the cool steel. Behind the bottle, the windowsill was a cool dark red-brown, its image curved into an ellipse by the bottle. I also saw cool midvalues on the surface of the liquid and under the black bottle cap. In no case did I paint the glass but instead tried very hard to paint the distortions and color shifts in the objects and in the reflection on the shoulder of the bottle.

"Linseed oil," oil on panel, 3x5, 2011

Here is another bottle, this time filled with a golden, translucent liquid (linseed oil). The liquid is dense enough to fully disperse the light as it passes through, effectively making the bottle translucent. I sketched this on a tiny panel in perhaps twenty minutes, my interest mostly centering on the light and glass. The setting and light are very similar to the bottle above, but the windowsill was eliminated for simplicity sake. The way the liquid was affected meant a darker and redder value toward the bottle side nearest the light and again a higher value reflection on the bottom. That light is also more yellow. The surface was the back of a canvas panel, though the color was invented. I added a warm red, broken ellipse to set off the bottom of the bottle. 

"Ellipses," oil on panel, 4x6, 2011

When drawing or painting anything cylindrical or spherical, one of the most important points to remember is that ellipses are key. In this sketch of a partly-filled goldfish bowl, there are at least a half-dozen ellipses, and each had to be correct. The bowl is set at the edge of a stainless steel table pulled about six inches back from the same windowsill as the sketches above. Here the light enters at a slightly higher angle. Since it's outside light, the shadows are cool, even where dark. Again the darker portion of water is to the right, toward the light, and the light bounces out of the bottom. The dark gap between table and window is shown in the small dark patch in the water, which nicely contrasts with the bright bottom. The surface of the water, the meniscus at the edges, and the dark reflection on the brighter side of the bowl all serve to define the glass, but nowhere is the glass itself painted. I also punched the color in the blue and ocher of the water inside the bowl, to help show the changing of light as it passes through. 

So ignore the glass and instead draw or paint what the glass does to the things around it.