The blue underpainting

It’s all paperwork for a few days, so, having no artwork to show you, I thought I could still add to my ‘how to do stuff” series of the painting techniques I use. The techniques I developed for myself, so I don’t know if these all these techniques have a proper name – I am simply showing you how I do it! Feel free to leave a comment if you use a similar technique, if you have anything to add, or just if you feel like it!

The Principle

The fairy of 'Euphorbia Lathryis', at the blue underpainting stage.
The fairy of ‘Euphorbia Lathryis’, at the blue underpainting stage.

This technique of blue underpainting forms the beginning of most of my paintings now. This is the first stage: the ‘shading’ part of my painting.  At this point I am simply concerned with building up a monochromatic version of the painting, shading the painting in terms of lights and darks. Colour is added in a later stage.

I have first drawn the image onto stretched watercolour paper, in pencil. Then the image is built up by thin washes of Prussian blue, (and generally no other colour), little by little until there is quite a lot of detail and ‘shading’ is quite nicely defined.

The Materials

The colour used here is Prussian Blue, from Winsor & Newton’s designer’s gouache range.

Prussian Blue is a very dark, translucent blue colour, which, thinned down, appears very like ink, and used very thickly has  a dark, oily-purple gleam to it, though of course it’s still a water-based paint not an oil paint. The important aspect of this paint is that it stains the paper: the colour will stay on the paper even when washed with water.

I actually prefer to use Horadam Gouache paints, made by Schminke, but for some reason their Prussian Blue is not very staining, so I stick with Winsor & Newton for that colour.

The Tequnique

Three different concentrations of Prussian Blue gouache, with water.
Three different concentrations of Prussian Blue gouache, with water.

The simplest way I have found to work is this: using a pallet with deep compartments (opposite), add a reasonable amount of water to three or four of the compartments and add a little of the Prussian blue to each of them so that you have three or four different concentrations of paint. Test the mixtures by getting a piece of paper and painting out each of the concentrations. You want a very pale tint, a fairly strong tint, and one or two tints in-between.

You can use this mixture for a few hours, or a day, but the Prussian blue eventually settles out as a gritty looking suspension in water, so I would recommend that the next day, or several hours later, you mix up more paint.

Now having mixed the paint you can work quite quickly laying on washes of paint and not have to keep mixing up the washes, simply add the darker or lighter washes as you see fit. To start with you’ll probably work mostly from the light tint, gradually adding brush strokes of the darker tints as you find where you want the darker areas to be.

What you are adding, therefore, is mostly water, with a tiny bit of paint each time, too. The paper should be allowed to dry in any one place before more paint is added, but if you are working on an image of any size other than very tiny, this will probably not be a problem: if the paper is still wet in one place, move to a different area and add paint to another part of the image.

Sometimes, if you want to have a fine graduation from colour to white paper, it can help to work with two paintbrushes. Use one to add the wash of paint, and the second brush only has water on it and can be used to soften the edge of the painted area. Usually I find that this is not necessary, though, because I’m adding so many thin washes of paint so gradually that the image is already fairly well modulated without the need for softening the edge with water.

One of the other things I do at this stage is to gradually rub out some of the pencil lines, or at least lighten them so they will not show, or not be overly obvious, in the finished painting.

And finally, one more thing I have to add is at this stage I am usually not concerned with adding any paint to the background: a dark background can be achieved with a dark colour at the ‘colouring-in’ stage.

Colour would come next, but that’s for another post… Here are a few paintings at the blue underpainting stage:

Blue underpainting, part way through: 'The Fairy of Ricinus Communis'
Blue underpainting, part way through: ‘The Fairy of Ricinus Communis’
Blue underpainting, finished: 'The Fairy of Ricinus Communis'
Blue underpainting, finished: ‘The Fairy of Ricinus Communis’
Blue underpainting: 'November masquerade'
Blue underpainting: ‘November masquerade’
Blue underpainting: 'The Intrepid Explorer'
Blue underpainting: ‘The Intrepid Explorer’
Blue underpainting: 'Medusa's Hammock'
Blue underpainting: ‘Medusa’s Hammock’
Blue underpainting (detail): 'Medusa's Hammock'
Blue underpainting (detail): ‘Medusa’s Hammock’
Mrs Minotaur II - blue underpainting
Mrs Minotaur II – blue underpainting stage. In this case i used quite a lot of pencil, to strengthen the darkest tones of the hedges especially. More usually now I rub out quite a lot of this pencil as I go along.

Blue underpainting stage for 'A Murder of Crows', with gold leaf
Blue underpainting stage for ‘A Murder of Crows’, with gold leaf