Cleaning of the frescoes in the Sistine Chapel has revealed Michelangelo as a bold colorist whose brushwork is characterized as impressionistic. The cleaning method is described, but the chemicals used are not identifled. The lunettes were painted freehand; areas lack intonaco. The Last Judgment will be the most demanding part of the restoration project; the fresco has accumulated heavy deposits of soot and grime, and previous restorations have damaged the original paint. Visitor traffic continues to pose problems during the conservation treatment. -- AATA