Early photographs of American folk paintings constitute a unique archive of works by both recognized and unknown artists, frequently even preserving a visual record of otherwise unknown paintings. A large number of early daguerreotypists practiced this lucrative work at a time when photography afforded Americans their first opportunity to have accurate copies of works of art, especially much desired copies of portraits of family members lost to death or distance. These copy images vary greatly in quality and interest, from mere duplicates to works of art in their own right. Between 1840 and 1860 most were produced by three photographic methods—as daguerreotypes, ambrotypes, and tintypes, each of which produced a single copy. By 1860, negative-based cartes-de-visite, inexpensive and readily available in multiples, effectively wiped out the earlier techniques. Surviving advertisements, broadsides, trade cards, and labels document that photographers from itinerant practitioners to the most famous studios in major cities offered copy work.