Sketching in the Underdrawing
- Small canvas or a panel prepared with a mid grey/brown value.
- 2-3 flat brushes (¼-1 inch wide)
- 2 small pointed brushes
- Piece of soft charcoal
- Titanium White Oil Paint
- Cadmium Red Oil Paint
- Yellow Ochre Oil Paint
- Ivory Black Oil Paint
- Thinner (I recommend odourless mineral spirits (OMS))
- Linseed Oil
- Painting rag or kitchen paper towel for wiping back and cleaning
- Working from life or from a reference, begin lightly sketching in the main shapes lightly with charcoal. As always, begin with the largest proportions before refining the lines and shapes. Try to use primarily straight lines as these are easy to correct and look confident. Don’t draw too heavily with the charcoal as this will darken your paint when you work over the top of the underdrawing.
- It’s best to take measurements with your eye rather than with a tool, but if necessary, you can use a spare brush to check that the proportions in your painting match the reference or sitter.
- Once you have lightly sketched in the major lines and shapes with charcoal you can switch to paint. Mix all four colours to make a mid-dark value muddy/neutral colour. Using a small brush dipped in OMS, work over the top of your charcoal underdrawing, tracing over the charcoal lines.
- If you need to make any corrections, dip a clean brush into your pot of mineral spirits and use it to wipe away the mistake. If any marks remain (or too much mineral spirits) you can use a clean piece of kitchen towel or rag to wipe away the excess.
- Once the line drawing is loosely sketched in, you can begin filling in the shapes with diluted paint (the same mixture you were using for the line drawing). To speed things up, you can switch to a broader brush for this step.
- Sometimes adding a tone to the shadow shapes will make you notice mistakes that you may have missed when it was a line drawing. Take the time to make any final corrections to the shadow shapes before leaving it to dry.
- Once you’re happy with the shapes, wash your brushes and palette and leave the painting until dry to the touch (at least 2-3 days).