One of the most intimidating things for a painting student is painting glass objects, mirrors, and other reflective or transparent surfaces. Like any painting technique, painting reflections requires practice and persistence. Painting reflections actually isn’t that difficult, if you can teach yourself to find patterns and look at the subject matter abstractly.
Learn to paint reflective objects by working from observation. Set up a still life with simple glass objects, such as wine bottles, vases and bottles. Also include non-reflective objects to create interesting reflections on and distortions in the glass objects. The still life should be in an area where you can control the light, as natural light will change the reflections while you are trying to paint them.
Start with a rough sketch of the still life on your canvas using a thinned wash of a light-color paint.
Identify the major dark colors and the major light colors in the still life and mix these colors on your palette. You should have several colors to start with. More can be created as you paint. Avoid using black as this can result in a painting that looks flat. Try to see color, even in what at first comes across as black.
Observe the network of smaller color shapes created by light, shadow, contour and reflection that make up the objects. Paint each color shape individually. Pay attention to whether edges between shapes are soft or hard. Blend minimally and keep each shape intact, not allowing them to get brushed together. Think of it as creating a mosaic out of broken tiles.
Allow the painting to dry.
Brighten or add depth to any areas that need it with a glaze. A glaze is thin, translucent color made by mixing paint with a glazing medium. Use glazing in any area that you think could be enriched with a subtle tint of another color.
Finish off by adding any glints of light (or highlights) you see. These glints are very light and will stand up sharply from the glass. To create these glints, take up a little dab of a barely off-white color with a small brush and just touch the brush to these points. Leave it alone after you add a glint, as blending will ruin the effect.