This is a quick little demo I did for my evening oil painting students last night. There is something intriguing about glass painted alla prima, it seems as if it should be impossible to depict a transparent, hard edged surface in a loose impressionistic way. When done right, this effect can be more eloquent than a tightly rendered, photo-realistic representation of the reflections and transparency. To achieve the desired result, it’s important to remember to place colors next to one another and not to overblend. Working wet-into-wet is challenging, dark values should be placed first, followed by mid-tones and brights, with highlights applied on top in the last pass. To get the highlights to lay on top of wet paint, be sure the paint is thick and opaque. I don’t use any medium for the highlights. I mix a bit of blue violet into titanium white for the cool highlights, and a bit of yellow ochre into the white for the warm ones. I prefer a soft, angled or flat brush and quickly stroke on the highlights in one pass.
Glass Alla Prima