Last weekend I participated in a natural pigments class given through Phipps Center for the Arts in Hudson, Wisconsin, taught by painter Gloria Adrian. The Phipps hosts an ongoing conversation on sustainability and the arts, called What We Need is Here, (after the Wendell Berry poem). Gloria brought many samples of colored clays and dirt from the region, and some coal in the form of "coke." She taught us how to make egg tempera, and then we played with the pigments for a few hours, painting samples on gessoed board. I brought some washi pasted with a couple of my patterns, and some soy milk. These samples don't look like much yet because I need to build up more layers of pigment and let the paint cure before washing the paste out. Generally, the pigments we tried had more sediment than the ones I use (from my teacher, John Marshall-on this page he describes the sources of the pigments he sells). The local dirt and clay colors are beautiful and muted. I look forward to trying them on fabric! Gloria also shared another great resource for artist materials including natural pigments, Kremer Pigments. They are based in Germany but also have an outlet in NYC.
The brilliant rust and ultramarine are pigments out of a jar, very similar to what I use, but from Kremer. The ultramarine contains some proportion of lapiz lazuli. I think the egg tempera adds a yellow cast to the pigments.
The samples in the jars below are all from local dirt, clay, and rock.