Tommy, grisaille portrait painting, oil on canvas. Painted with Titanium White and Ivory Black. This is a typical grisaille underpainting before the colour glazes of oil paint

Tommy- underpainting in progress. Underpainting is a technique used since the renaissance. It usually refers to a monochrome foundation or base layer, and layers of paint are applied on top. This one is a grisaille or grey, but there are various different kinds, and not always of the monochromatic variety. Titian used coloured underpainting. The idea is that it supports further layers of paint, as a foundation supports a house. For me it is purely a pragmatic solution where I can be confident that the drawing is correct and can continue applying further colour layers without having to backtrack and amend the drawing as I go. If I’m painting a portrait to commission I like to work as efficiently as possible, and in the past I have found myself in tricky situations where I have had to keep going over the drawing because its not right, and this can be very time consuming. As I have said elsewhere, you can throw a lot of good painting after bad if the drawing isn’t right first.

The other type of underpainting I have used is called ‘verdaccio’, which is a green version, and usually made by mixing black, yellow and white although I think a nice version would be with Michael Harding’s Sap Green and Titanium White only.  I never used black as my art teacher at school was a hardcore impressionist with a love of purple who could not abide it. Honestly it took me 20 or more years to get over that – just couldn’t use the stuff.

Anyway there were a lot of impressionists or those painting at the same time who loved a good bit of black, think Manet and Degas. But we were taught to mix optical blacks with reds and greens or browns an blues and these are very beautiful, and deeper than your average black in a tube. When I learned how to mix oil paint for skin tones from Louis Smith using reds and greens, that struck a chord with my earlier learning and its stayed with me as the basis of all the glazes I’ve found the most useful when painting portraits.

In every portrait painting I paint using the grisaille method, I use the same mix of Alizarin Crimson, Cadmium Red and Sap Green to start off (has to be a warm Sap Green – Michael Harding does a beautiful but cooler version which is different to the one I need). I have a Winton Sap Green that is good for now. Maybe a little Raw Umber as well.. All the other glazes I mix hover around this mix on the palette, depending on the person I am painting of course.