Week 3 & 4 : Opalescent Imprimatura Portrait Study

You will need:

  • A canvas approx a3 size
  • Acrylic:
    Caput mortum / mars red / venetian red / burnt sienna (a red)
    Gamboge yellow / primrose yellow / cobalt yellow etc (a yellow used semi transparently)
    Ultramarine blue / prussian blue / cobalt blue (a blue used semi transparently)
    Acrylic gesso or titanium white gesso
  • A sponge (synthetic, not coarse organic sponge)
  • Titanium white pigment
  • Oils
    Recommended include
    The earths
    The mars
  • Tempera grassa titanium white or if lacking, lead white oil (mica lead white recommended) or titanium white oil
  • Venetian medium (stand or cold pressed linseed oil, gum turpentine, small amount of canada balsalm or damar)
  • A reference color portrait photograph of high detail, low lenticular distortion
  • Recommended : Access to photoshop
  • Access to printer

Summary : To explore combining some of the aspects of our learning so far : imprimatura, transfer of cartoon, value study, and aspects of color matching and applying upon tempera grassa in transparent oil.

The human skin is of complex subtle texture and color range in the microcosm. The use of an imprimatura combining the primary colors to achieve an ‘opalescence’ to play underneath intentional skin tones is employed.

Step One : Identify and prepare suitable portrait

This can be of someone you know or an image you find that you wish to paint.

The important thing is that you look for the suitable value scale we have gained some understanding of through our value studies – you look for a photograph that has a good range of values from dark to light, but with a lot of subtle information in the midtones.

We are going to print out the image but first make some useful steps in photoshop if we have photoshop.

Step 2 : Photoshop (helpful but optional)

Copy the image file so you have 3 copies.

Import one of these copies into photoshop. Observe the photograph. Observe the diversity of colors that make up skin. We are going to do a little proceedure to simplify this.

Original image with much complex color information

We will run a smart blur upon the image in order to generalise the colors much the way a painter must do. Find under Filter>Blur>Smart blur. Try with radius 3.0 and threshold 7.

smart filter smooths information before posterising
Smart filter smooths information before posterising

Then we will posterise around 24 levels. Find this option under found under menu Image > Adjustments. This means the image is simplified to 24 differences of color and value.

The posterise option is found under Image > Adjustments

Observe below the difference we have achieved which will make the process of color matching skin tones hugely simplified.

finished simplifying portrait
Finished simplying color information whilst preserving true colors.

Now you have prepared your ‘posterised’ (simplifed) color reference, print it x2 at high quality at the size you wish to paint it.

Also print 2x versions of the posterised image in greyscale (black and white) at the size you wish to paint it.

You now have 1 posterised color image. 1 posterised greyscale image. And 1 proper unedited image.

Make sure one of your greyscale images is printed on fairly thin normal stationary paper. We will sacrifice this print transfering it.

Step 2 – Rendering an ‘opalescent’ imprimatura.

The purpose of this proceedure is to create an imprimatura that contains color complexity.
These colors will play through the intentional skin-tones we apply through glazes later.

Step one: Render imprimatura.
Mars violet is recommended but could use venetian red.
Acrylic can be used, or oil paint. Apply oil leanly with 2/3 gum turps (or mineral spirit) to oil (stand or cold pressed).
Allow to completely dry before next step!

Step two: Sponge on white
Use acrylic gesso or titanium white acrylic on moistened sponge. Experiment first on practice offcut to get the consistency right. It should look like a speckly, mottled effect that shows through some of the red in places.
Allow to completely dry before next step!

Step three: Apply yellow. Recommended : Transparent Yellow Oxide. Can use gold oxide or gamboge yellow or yellow ochre or any manner of variations.
Use clean sponge in similar manner as step two, to apply a mottled, speckly interface of yellow upon the red-white. The yellow should not ‘cover’ the red or white entirely. It is a balance to allow all to have co-existence.
Allow to completely dry before next step!

Step four: Apply blue. Recommended : prussian blue mixed with a very small amout of white. Alternatives: Ultramarine blue, cobalt blue etc
Use clean sponge in similar manner as step two, to apply a mottled, speckly interface of blue upon the yellow-red-white. The blue should not ‘cover’ the red, yellow or white entirely. It is a balance to allow all to have co-existence. See photos for example.