As a young art conservator at the Winterthur museum near Wilmington,
Del., Richard Wolbers was assigned an early 19th century painting that
needed cleaning. It was Jacob Eichholtz's portrait of Ann Ross Hopkins,
grand-daughter of George Ross, one of the Pennsylvania signers of the
Declaration of Independence. The oil paint had been covered with a
coating of varnish, and applications of linseed oil had dulled the
appearance of the portrait.