Diane asked: “You showed a technique for portraits involving the use of charcoal and an eraser. The results were impressive. Is there a way of applying this technique to acrylic painting?”
Diane’s referring to one of my favorite techniques for getting an image to resolve – building a value study from a mid tone. This works superbly well in charcoal: Methods Page – More on Value Studies – working from a mid-tone in charcoal…and paint! The same principles do indeed work well in both oil and acrylic – the problem with acrylic is that it dries so fast you have to be fairly quick as the technique involves wiping off paint. Evidently this relies on the paint still being wet!
The method is generally termed “wipeout underpainting ” and is a classic technique cherished by traditional oil painters: http://www.aristidesatelier.com/blog/wipeout-underpainting. A thin ground of mid-tone paint is first applied and then wiped-off with rag and dry brush (eg “erased”) to reveal the white of the canvas. Dark areas are punched in with more saturated paint.The process almost exactly parallels the charcoal technique.
With acrylic, adding some medium and retarder to slow drying is a good idea – or use slow drying acrylics (the best known being perhaps the Golden “Open Acrylics” series). When the paint starts to dry (as it inevitably will!) I switch to using some titanium white for lights. With that goes the purity of the technique, however it does get the job done. I use this technique frequently these days. I prefer to undertake low-tone underpainting in acrylic rather than break out the solvent and oils.
Break-a-Brush!
David