Signing dating paintings
Claude began keeping this sketchbook around 1635 in an effort to keep the forgers of his work at bay.
The Liber Veritatis was the first document of its kind in the history of art, and has enormous historical as well as aesthetic value.
Signatures, especially like those of Vermeer which are painted little more than a wisp of paint, are particularly vulnerable to the vicissitudes of time and the processes of conservation.
Signatures of traditional painting are generally not applied directly into a substantial layer of wet paint (i.e., wet-in-wet technique) but superimposed over the lower layer of paint once it has become thoroughly dry, at the very last stage of the painting process. It should be considered if the signature location is typical compared to other known examples of the artist.
Claude Lorrain's eerily beautiful landscape paintings have enchanted the art-loving public for centuries, making this French painter one of the most widely beloved artists of the Baroque.
Building on the base of the ideal landscape created by his predecessors and contemporaries, particularly early Italian Baroque painter Annibale Carracci, fellow French Baroque painter Nicolas Poussin and Paul Bril, Claude Lorrain was perhaps the most influential landscape painter in the history of art and paved the way for generations of landscape painters to come.
Cave art was once considered evidence of a "creative explosion", when the minds of ancient humans became fully developed: today, scholars believe that human progress towards behavioral modernity began in Africa and developed much more slowly.
The oldest yet dated cave art is from El Castillo Cave, in Spain.
Microscopic examination of the signature is usually, but not always, able to evidence the signature's uniformity with the rest of the painting.
Claude had some immediate followers in Italy and France in the late 17th and early 18th centuries (most notably his pupil, Angeluccio, Salvatore Rosa, and Claude Joseph Vernet), but Claude's greatest influence was felt in England. Furthermore, Claude Lorrain was an absolutely superior draftsman, and in fact his paintings have on occasion inspired less interest than his free, spontaneous sketches of nature.
Claude's paintings impacted all aspects of English culture, from literature to garden design, and English artists were by no means immune to this influence. Over 1,000 extant drawings have been attributed to the artist.
Although now known as one of the famous painters of the 17th century, the Dutch painter Judith Leyster (1609-1660) virtually disappeared from the history of painting after her death.
Over 200 years later in 1893, the Louvre museum unearthed Leyster's unique monogram under the fabricated signature of "Frans Hals", whom many believe to have been her teacher.