20_Pigments

I concede, my hidden agenda behind fresco is to push colors.

A quick color study in fresco, where I pursued the color chords I yearn for (even if I did not succeed):


I am reaching for brighter color chords than either oils or acrylics can deliver. The young, wet fresco accepts raw pigments, and thus starts with cleaner hues, unmuffled by the glue binders used in paint. Dry fresco pushes that color towards a livelier transparency, by bouncing the sunlight off its harsh white lime support, and back again through those raw, applied pigments. Thus, in order to lighten a hue, the fresco artist merely lays his pigment on thinly and lets the light radiate through it, rather than dull that color down with an opaque titanium white, like an oil painter does. If the artist tunes his transparencies well enough with the opaque colors, the final fresco mural should invite viewers to breath in the vibrant colors, and enjoy the spectrum on a visceral level. Or at least this is my theory. The unobtrusive matte surface of a buon fresco just makes color all that more accessible.

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The fresco pigments we used came from Mayan Pigments Inc and Sinopia, and a couple of found rocks which we crushed into powder .

Below is a belated color chart, on a fresco made from Sinopia pit lime mixed with marble dust. The first 2 rows are Mayacrom® colors, followed mostly by pigments bought at Sinopia. The dull smudge in the middle is a Sinopia white obsidian from Mexico.

In the lower left corner, the larger stroke is from a green rock I found in Arizona, and crushed to make pigment. It does not cover evenly, as if there were some silt in the green color which separated after it was applied. The square below that is a fine red pigment for polishing gold, which I bought at Starr Gems, but does not cover evenly either:



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Maya Blue

In fresco, blue is the most evasive color. The medieval artists prized lapis lazuli, which in the 15th century was an ordeal to make, only to be trusted to the dainty hands of pretty girls according to Cennino Cennini, and thus was more expensive than gold. However, this blue color fades into nothing when applied to wet alkaline lime, and thus cannot be used in buon fresco. Medieval artists resorted to second best, and applied the blue after the mural dried, using the fresco secco technique.

The affordable ultramarine blue we have today is chemically the same as the semi-precious lapis lazuli, so it can be used in fresco only if "stabilized" first. Regular ultramarine blue will fade in fresco like expensive lapis lazuli, from a brilliant blue to nothing in 4 days. However in our times, we also have cobalt and pthalo blue, which do work in buon fresco painting.

Ancient Mayan artists enjoyed an advantage over their medieval European counterparts, having developed the lime-proof Maya blue that survives well in buon frescoes, such as the one at Bonampak.

However, when I went to art school in Mexico City in the 1990s, I learned that modern science could not make Maya blue pigment. Since then, I had been Googling "Mayan Blue," and was pleasantly surprised to find that chemists at UTEP in El Paso, and the Instituto Nacional de Investigaciones Nucleares in Mexico City, had recently discovered the secret and were now making their own Maya blue color.

I am especially grateful that the CEO of Mayan Pigments Inc. gave me some Mayacrom Blue® to paint with , as well as some other new pigments which they developed from the same technology. I felt very privileged grinding the Maya blue color developed in the new world, to use in our contemporary American fresco paintings:



All the non-toxic Mayacrom® colors were a pleasure to work with. They hardly raised any visible dust when I tapped small quantities out onto a glass plate, from the spice jars I used to store them. Moreover, the Mayacrom® pigments mixed well in water too, unlike the pthalos and other bright chemical pigments.

I used the small glass muller, which I commissioned from Fathead on 4th Avenue in Tucson, to grind the pigment into distilled water for painting on fresco:



Grinding MayaCrom® yellow:



Mayacrom® violet, yellow, and blue. Raw pigments in tubs, pigments ground in distilled water and stored in flip top bottles, and a fresco color chart of those 3 colors:


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Fresco Color Charts

I prepared small fresco color charts. I cut industrial foam board from Home Depot into rectangles that would fit into a plastic pencil box. Then I gessoed that board with Golden Sandable Hard Gesso. The next day I troweled wet fresco plaster halfway over each board:


Golden Sandable Hard Gesso for priming the boards; color chart of opaque Sinopia yellow ochres and transparent Mayacrom® yellow; and a torn sample of the industrial foam board support from Home Depot:


Color chart made from Mayacrom Red® and 3 Sinopia red iron oxide pigments:


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"Grinding" Mass Quantities of Pigment

Fresco does not use as much pigment as oil painting. Thus I just employed a small glass muller to grind limited amounts of pigment quickly into distilled water, which I then stored in flip top bottles.

I do wonder whether I have ground my pigment enough. I have heard that "the longer one grinds the pigment (into water), the better," perhaps because a well-ground pigment penetrates deeper into the wet fresco surface. I remember that Jose Galindo said he ground his pigments over night in a rock tumbler, when he was teaching me the fresco technique. Not only did this mechanical process grind the pigments longer, but ground larger quantities as well:


I bought a cheap kid's rock tumbler at Michaels, which leaked, and therefore did NOT work:


I did NOT grind pigments with the cheap child's rock tumbler. I bought additional "media" -- cheap plastic pellets (at Starr Gems) and kid's glass marbles -- that would "grind" the pigment into distilled water. However, afterwards I noticed that the red container leaked water when spinning. It would be a disaster if this container leaked strong pigments that stained!


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"Found" Earth Pigments

I suspect that biologically, we humans are visually tuned to natural earth pigments, in order to distinguish between nuances in red earth, for example, for survival purposes. Moreover, reserved earth hues might look better in large areas, like in fresco murals, than do the higher chroma synthetic colors, more popular in the artist paint stores. Aspiring to escape the high-key color signature of the acrylic painting of our times, I started wondering if I could deliver satisfaction through subtle variations of earth colors. Moreover, I'm attracted to the poetically correct aesthetic of using "found" earth colors from the Southwest, to paint in more immediate themes. My aim pales, however, next to the accomplishments of Juan Quezada, who revived the pottery tradition of Paquime (native American ruins just below the US border in Chihuahua, Mexico), after he discovered the local sources of ancient earth pigments -- establishing the fine art pottery of Mata Ortiz.

Thus I started pulverizing colored rocks to make my own natural pigments, like these subtle greens that I made from Arizona rocks:



I wanted to catalog the pigments I found on the side of the road. Here I bagged some red volcanic earth, photographed it (image below), and added GPS coordinates to the photo. This way one can go to Google Maps to see the location from where the pigment came:

• If one had the free XnView image software on his computer, he could right click the thumbnail of the below image (after he downloaded it), and choose "Open GPS location in Google Maps." If he were online, his browser would open, showing a map and satellite picture of the location where that pigment came from.
  

• I bought a GPS device that assigns global coordinates to digital photographs (AGL3080: Amod Technology GPS Photo Tracker), using software such as the free GPicSync.

Green and blue pigments in Arizona:


I used a porcelain mortar and pestle to smash the green rocks into pigment dust:


I should have smashed the larger rocks in a metal mortar first:


Later I mixed greenish dust into water with a palette knife:


Then Ernie introduced me to better technology; specifically the electric pencil engraver he bought used at a tool store:


Ernie shaving the color off found rocks with the electric pencil engraver:

Plates of colored dusts that Ernie shaved off found rocks with the electric pencil engraver:

Joshua also crushed found Arizona rocks into gorgeous pigment:


Below is Joshua Woodhall's oil painting, which he derived entirely from natural pigments, that he made from found rocks he crushed. This beautiful canvas is currently hanging in the Solar Culture Gallery:


My kit for making homemade earth pigment from found rocks:


The iron object at the far right is a mortar and pestle (Plattner's) for crushing small rocks. I sift the colored dust through the round screen at the far left (mini sieve), then sift it again through the finest silk screen material I could find (the orange cloth pictured), to make pigment:



Tools for breaking down the rocks -- hammer, sharp scrapers, brush, plastic tray:

Earlier in the year, Ernie lent me a jar of red hematite pigment, which he had crushed himself from rock. I ground it into linseed oil to make oil paint:

I also bought some other powdered colors at the Gem Show 2009 in Tucson. I ground the turquoise and malachite into linseed oil to make oil paint:

The difference of two semi-precious greenish stones, bought as powders, and ground in oil:

Painted with turquoise ground in oil (which went green rather than blue):




Deborah curated a pigment exhibit at the El Paso Museum of Archaeology, from February to May, showcasing local pigments that were used for ancient rock art:

Deborah cleverly recreated a rough rock surface in a hard, thick paper mass, to show how the pigments looked and behaved when mixed in different paint mediums (I sent her the turquoise sample in the front). While rock art is not the same as fresco, the techniques can share something of the same natural aesthetic:

The El Paso Museum of Archaeology also had a more permanent exhibit, of local pre-contact pigments:

This is the pigment display at the museum at the ancient Kuaua pueblo, outside Albuquerque, where the famous pre-Hispanic "fresco" murals are displayed -- turquoise, red ochre hematite, kaolin white, limonite yellow:

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Medieval Pigments in Arizona


The Ciudad Rodrigo Altarpieces by Fernando Gallego's shop have been on display at the University of Arizona Art Museum since September, 2008. Earlier this year they exhibited the x-ray photos of the under drawings, and enumerated the pigments used:

I was surprised to see that the medieval painters used quartz as white (not mentioned by Cennino Cennini):

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Lime-Proof Colors

Not all pigments will work in fresco. The alkaline lime can kill particular colors ( such as this previously mentioned ultramarine blue that faded in 4 days).

I suspected that if the color is not "lime proof," it would fade almost immediately. I conducted a test to confirm my suspcions, and spread some fresh organic cochineal color (thanks to the Roadrunner Hostel in Tucson) onto the Sinopia pit lime:

2 days later, the cochineal on the lime was as strong in color as the cochineal on the inert plastic. In fact, several weeks later the cochineal had not faded either, appearing as intense as it did the day I spread it onto the lime. So this experiment backfired:

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Conclusion

In the spirit of our cherished Maya blue, I have encountered other obscure blue pigments, such as the Aztec Matlali blue (Sonoran Guaiacum) I read about online. I remember that Carl Von Hassler used an unusual toxic blue to paint the murals in the Kimo Theatre in downtown Albuquerque. Just recently, I read that Mas Subramanian's team discovered a new blue pigment at Oregon State University.




I must add that I find inspiration from the Anarchestra in Tucson, for breaking musical instruments down into their abstract essentials, in order to create new instruments of welded scrap iron. In this way they might step far enough outside of the conventional orchestra to pursue new colors in sound. Likewise, I hope that by breaking color and painting techniques down to the basics, I might then refine minor color cords or invent novel color scales, and deliver different chromatic sensations, short of a new color, from a painting in any medium: