Master of Plaster : Art: A fresco expert offers insights into the demanding medium. His mistakes are etched in stone.

Fresco never forgets.

In most artistic media, a mistake can be erased or covered up. But when artist Frederico Vigil is painting on fresh plaster, any slip of the brush quickly turns to stone. The only way to change a fresco once the pigment has been applied is to chip away the offending layers of plaster and start anew. Like live television, it is no medium for the faint of heart.

Vigil, 46, has just completed a fresco called El Quinto Sol, “the Fifth Sun,� at the Social and Public Art Resource Center in Venice. The 46-year-old Santa Fe native also taught a summerlong seminar in the ancient art, resulting in a second fresco by seven of his students.

A SPARC news release describes Vigil’s 9-by-11-foot work as “an allegory on the city, depicting a woman pregnant with the future, surrounded by imagery of the streets.� Well, maybe. In an interview, Vigil says the work is about mural painting. He points to visual references to Michelangelo’s depiction of the Creation on the ceiling of the Sistine Chapel, arguably the greatest fresco of all time, and to more recent works by Mexican masters Diego Rivera and David Alfaro Siqueiros.

There are also in the work allusions to the ancient cave paintings of the local Chumash Indians and to the natural pigments fresco artists use because, if you use man-made pigments, “the lime will eat them.�

Vigil, a Santa Fe artist who is largely self-taught, learned fresco in 1984 from Lucienne Bloch and Stephen Pope Dimitroff, apprentices to the great Rivera. Dimitroff taught him the chemical engineering of fresco, how to mix lime, cement and sand in the proper proportions and how to apply the mixture, five layers thick, creating the surface to be decorated.

From the pair, he learned how to sketch his design or sinopia on the smooth, third layer of plaster. He also mastered the craft of transferring the sinopia onto tracing paper, creating a cartoon. After waiting weeks to let the first three plaster layers dry, the two final layers are applied.

The top layer is called the intonaco . Before the fresco can be painted, the design is transferred from the cartoon by perforating the lines on the tracing cartoon, holding the cartoon up to the wet plaster and “pouncing� the pattern with powdered charcoal. Guided by this simulation of the design that lies underneath the wet plaster, the artist must paint the fresco, in manageable sections, before the plaster dries. The result is a durable medium characterized by deep, glowing color. “It’s alive,� Vigil says. “We’re creating a rock, limestone with color.�

Vigil says he enjoyed working in Los Angeles, which has become the center of mural art in America. He points to such distinguished predecessors as Jose Clemente Orozco, who created major works in Claremont. Vigil, who worked mostly in acrylics before, says that fresco is now his medium of choice. “There’s nothing else I want to do at this point.�

At SPARC the artist experimented with plaster mixtures rich in barium carbonate that may or may not prevent pollution damage, a plague the Minoan fresco artists and Leonardo da Vinci didn’t have to worry about. Vigil was largely pleased with his work as it progressed. He only scraped back and started over on two of the eight sections into which he divided the work. The mural was dedicated at the end of last month.

Vigil points out that the two frescoes, on outside walls at SPARC, are removable. He is also experimenting with smaller portable frescoes in his Santa Fe studio.

Local artist Alma Lopez, who took the seminar, said she found the work demanding but rewarding. The plastering, which would often take three to four hours per section, was tedious, but the painting itself was exhilarating, though initially intimidating, she said.

She countered her own performance anxiety by making her pigments as diluted as possible when she first began painting a section, adding more color as she became more confident. Among her contributions to the workshop fresco, called “City of Angels,� is a green frog, a reference to Sapo, or Toad, Frida Kahlo’s name for her exasperating lover, Rivera.

One observer noted that the two frescoes, which are filled with visual references to Latino culture, including tattoo and graffiti art, are Frida-free, without a single allusion to the ubiquitous Mexican artist and icon.

Fresco is a medium that has endured for thousands of years despite the tedium that it involves. Its creators are seen as larger than life, even by the standards that tend to transform artists into romantic creatures--Michelangelo lying on his back, struggling against back pain and papal meddling to depict the merging fingers of God and man.

Vigil’s work is enriched by thousands of years of tradition and by the knowledge that his art is sustained by a most demanding craft. But what really counts is the fresco itself, filled with the colors of the earth, a painting as durable as a mountain.