- Watch Mark Ryden Verdaille demo start to finish. I’ve heard he sometimes does the underpainting in acrylic with the top layers in oil paint. But it looks like in this demo – he is using thinned down oil in the underpainting. One trick to leaning out the first layer of underpainting, is to add more turpentine to the local color and/or add raw umber. Even though raw umber has a high oil content – it is has a quick drying rate (oxidation). The Painters Handbook by, Mark Gottsengen has an excellent table for discerning which colors are best for underpainting. Look for ones with low oil content and/or quick drying rate.