Michelangelo’s studies for the Sistine Chapel Ceiling have revealed the presence of under-drawing. I’ll discuss how science has addressed the mystery of whether restorers have reworked art by the ‘divine one’.

Michelangelo studied the pen and ink technique of parallel and cross hatching at the workshop of Domenico Ghirlandaio.

Artists and sculptors of the time (Michelangelo included) would sketch from live models or cadavers. Then, an artist may have made a bozzetto or bozzetti (plural) - small models made in terracotta or wax.

In 1987 infrared reflectography was used to determine if the figures on the Sistine Chapel had been reworked by restorers - a theory some art historians had introduced.

Michelangelo’s "Nude Figure Next to the Prophet Daniel" from "Studies for the Sistine Chapel Ceiling" at the Cleveland Museum of Art was determined by technology to have a black chalk under-drawing (which was probably erased) under red chalk; black chalk would have a more defined, precise line which could be directly drawn onto plaster.

Before painting the Sistine Chapel, Michelangelo experimented with wet chalk (for density) in his drawings, as seen in the Metropolitan Museum of Art, NY’s "Preparatory Study for Libyan Sibyl."

Another of Michelangelo’s techniques can be seen with his copy of Masaccio’s "Expulsion of Adam and Eve from Paradise" - using red chalk, probably heightened with white. This drawing can be found at the Louvre, Paris.

After scientific examination, it was determined that these drawings were almost identical to the Sistine Chapel frescoes. It is my belief that ultimately, the paramount goal in preserving the integrity of these art treasures must be uncompromised.

You can own the book by Klaus Albrecht Schroder, "Michelangelo: the Drawings of a Genius."