Many of my students enjoy the paintings of Dreama Tolle Perry (link) and Nancy Medina (link). Some of us have studied either in workshops or in e courses with these artists. Both Dreama and Nancy use an underpainting of rich transparent colors diluted slightly with linseed oil: gamsol (1:! mix) (Dreama) or Chroma Brand Archival Lean Medium (Nancy). Both darken their transparent under layer substantially before using opaque colors in the upper layers of the paintings. These opaque layers use no medium. Note that any paint (including the transparent paint) mixed with an opaque paint becomes by definition an opaque color.
This week, we identified and organized all of our paints into opaque and transparent colors.
We taped our transparent tubes for easy identification.
Whether a color is transparent or an opaque pigments can be found on the tubes themselves for many of the common brands we owned. Winsor and Newton has a square on the right upper back of its tubes. A blank square (one that you can see through) is the symbol that the paint is transparent: a solid black square (one that you cannot see through) is the symbol for opaque paint and a square that is half and half is semi-opaque. Rembrandt uses the same squares but theirs are located on the front left of their tubes. Sennelier has their squares on the top back left in the black name banner. The following brands print "transparent, opaque or semiopaque on their labels. Williamsburg has this listed on the back top under "Pigment". Gamblin writes in in capital letters on the back also under the pigment description. Richeson has a box on the lower back that lists the pigment properties. Michael Harding also prints theirs on the back in the pigment information. Perhaps the Japanese on the back of Holbein paints has this information but it is not something I can use. I cannot find this information on Old Holland tubes. With paints where this information is not found easily on the tubes, one can go on line and click on the "pigment information" tab for a particular color.
Our exercise to illustrate the properties of transparent compared to opaque colors had each class member identify (or if possible mix using transparent colors) a color that appeared similar in a transparent and an opaque tube. For example: top left transparent sap green. Second row left: sap green mixed with indian yellow, then opaque cinnabar green, transparent red medium by Rembrandt and opaque cadmium red.. Each color pair was applied thick to thin in a streak on the exercise board. The underlying canvas could be seen through the transparent strokes and not through the opaque ones. Tilting the surface so that the paint could be seen across the surface further illustrated the difference in the opacity of the pigments. In addition, even with the single matched pairs, we could begin to see that the opaque pigments advance.. This explains why our "go to" deep grey mixture of ultramarine blue and transparent oxide (both transparent colors) makes a rich deep dark. It also explains why the centers of the flowers that Dreama and Nancy make using their transparent mixtures stay in the depth of their flowers.
Next, we added white to each color pair. White dulled down the opaque member of all of the color pairs we tested. The transparent -white mixtures retains more color intensity (chroma).
This is my underpainting of transparent colors. Notice how well the dark transparents receed into the background. I have redefined my drawing in the wet paint using my wipeout or kemper tool (link). This allows me to apply the opaque colors more precisely. That way, there is more likely a clean deliberate stroke of opaque paint and less blending if I had to move things into the correct position,
The opaques have been added to complete the painting.