Preparing Earth Pigments

[Koo Schadler]

I imagine this question has been asked before, but I couldn't find the thread. Traveling in Mexico I found an exposed cliff wall full of earth pigments - purples, reds, yellows, greens. I've taken some home and played with them and they make beautiful paint. But I recognize that they should be processed before being used in an actual painting (i.e. to be archival). What are the various steps necessary to make an earth pigment suitable for painting? What are the drawbacks of working with pigments from the backyard that have not been washed, etc?

Koo

[George O'Hanlon]

Koo,

It is not difficult to prepare earth pigments for painting. Place the dirt in a bowl, add water, stir it and pour off the water along with some of the matter floating in the water. Do this several times to remove organic material. Allow to dry and grind if necessary.

[Koo Schadler]

Thanks, George. Sounds fun and I'll give it a go.Koo