Washington Allston used multiple glazes with fast driers, megilp and asphaltum, and a final toning called Titian's Dirt. James McNeill Whistler had profound interests in surfaces and harmonies and orchestrated both permanent and impermanent materials into alternating patterns in <i>Harmony in Blue and Gold, The Peacock Room</i>, which has also been modified by imbalanced past restoration efforts. A.P. Ryder used unorthodox nondrying materials which have caused traction crackle and immutable browning, but may be the key to distinguishing numerous forgeries from original works. Examination of contemporary bibliographic sources in conjunction with technical examination by conservators and art historians working in tandem is seen as a promising method to evaluate original and current appearance of works by these artists.