Check the condition of your lithographs. The restoration of rare or vintage lithographs can be done only by skilled paper conservators/restorers. Works of art on paper are extremely vulnerable and require special care and attention. Paper can be damaged by atmospheric pollution, humidity, acidity, chemicals, mold, insects and mishandling.
Take restorative measures if necessary. These serve three purposes: the elimination of conditions that cause potential or actual deterioration, the recovery of aesthetic appearance and the recovery of monetary value.
Make a deal with a conservator. Some conservators base their estimates on time, others on the difficulty of the required treatment and some on the monetary benefit that accrues to the client. Obtain estimates from more then one conservator.
Gather knowledge about your lithographs. The most accurate information on the value of lithographs comes from graphic arts councils and art collectors. The Graphic Arts Council of LACMA, UCLA Grunwald Center for the Graphic Arts, the Print Collectors Club in Philadelphia and Print Club of Cleveland are all good resources.
Contact Sotheby's International Print Department. First talk to its specialists about your lithographs. They will explain the procedure and the guidelines. Sotheby's has auctions in April, May and November. Make sure your contact it well in advance. Have a good auction!