I have been experimenting with painting icons using acrylic paints, after years of using egg tempera exclusively. I kind of like acrylics, with their ease of use and quick drying. Over time, I have studied with several different teachers, each with their own methods, and it has been interesting trying to find my own preferences and methods in my iconography.
I recently found myself fairly well pleased with a way to paint skin tones (sankir) with my very limited acrylic palette.
I use the paint directly from the tube, thinning it with equal parts water and Golden Fluid Matte Medium. Using only water gives you lovely transparency, but often there is a problem with lifting: the acrylic medium binds the paint to the surface, making it permanent. I mix the medium, water, and paint, using an old jar lid as a container, until it has the general consistency of heavy cream. Letting it sit for a couple of hours allows any bubbles to disperse. My palette is very limited: the colors in the photo are 95% of what I used to paint these faces. One can also use the same powdered pigments as in egg tempera: just use the acrylic medium instead of egg yolk for the binding agent to make the liquid paint.
I’ll go through my modest, cautious method (and there are many ways to make this work, this is just what I have stumbled upon) step by step, with this painting of St.Monica:
First, of course, I transfer the drawing to the board, line it with a mixture of red, ultramarine blue, and green to make a dark, dense color. I don’t often use black for anything. I then cover the entire board with a layer of yellow ochre to open the icon and provide a unifying harmonious color below the other layers of paint.
The first layer of the skin tone/sankir is Chromium Oxide Green with a bit of Yellow Ochre. It is pretty green and alarming–but don’t worry, it will work. Paint it on all skin and hair areas. If necessary, redraw most of the lines: upper eyelid, pupil, eyebrows, nose, mouth, chin.
Next I paint on, in the areas that will be highlighted with Cadmium Red Light. I am careful to blend in the edges at this early step as best as I can, using water to thin out and avoid sharp boundary lines.
Mix some Yellow Ochre, about half and half, with the red. Thin with water and acrylic medium to make it transparent. (Anytime you thin acrylics with water, remember to add in some medium. Otherwise the pigments might not bind properly and will lift off when you paint the next layer.) Apply this color as a base coat for the bright highlights. After this somewhat orangey layer, I use pure Yellow Ochre in transparent layers, until the features become distinct, moving gradually back away from the edges.
The brighter highlights are made by adding Titanium White to the Yellow Ochre. Float on transparent layers for a small icon, brush them on a larger one, using water and medium to dilute, soften and fade the edges so that there are no sharp boundaries.
As you paint, it can happen that the whitish paint layers come up too brightly, or the tones are too chalky. Fix this by putting a thin layer of transparent Red or Yellow Ochre –or both–over the entire skin and hair area, including the green shadow areas. These faint layers of red, then ochre, will soften the harsh green and red areas that are showing. They become more brown or olive in shade, depending on whether you push back the chalky areas with reds or ochres.
The transparent layers of reds or ochres will blend the entire skin tones beautifully, eliminating “islands” overly bright color. Use as many layers as you feel is necessary, going back and forth between painting on highlights and pushing them back. With each layer, the face emerges a bit more.
One nice thing about using this method is that it is never hopeless. You can always fix and correct anything. Paint it on, push it back. Just keep on tinkering with it, using the paint more like transparent water colors. Reline if necessary. Use a transparent layer of burnt sienna and green if you need to darken shadows.
Finally, once the skin tones are softly blended and look correct to your eye, use a 60-40 mixture of Titanium White to Yellow Ochre to do the brightest highlights. Pure white is too harsh. Paint in the dark lines (eyebrows, eyes, etc). And again, if they are too stark, push them back with a layer of Yellow Ochre over all again. Repaint if necessary. Put in pure red (transparent) lines along the nose, mouth, chin, around forehead, red spots in the corner of the eye and by the ear, and anywhere else that a warm emphatic line is useful.
I am sure that there are as many ways to do this as their are iconographers, but this method has worked for me. I hope this has been helpful to you. And as you might guess, some of the color differences in the illustrations are due to different lighting when I took the photo. All of them are different stages of one painted face, from start to finish.