History Wired: Rubel Offset Lithographic Press
A brief history and explanation of offset printing from the Smithsonian Institute
Identifying an offset print requires that you look very closely at your artwork – in some cases, you may need a magnifying glass, etc. One approach is to examine any disparity between the perceived versus the actual texture of the piece. If the “painting” appears to have a heavy impasto, thick brushstrokes, etc., but the surface is actually smooth (this examination may require you to remove the artwork from its frame), it’s most likely a photomechanical reproduction. If you can see a dot pattern, particularly in the darker areas of the piece, that’s an indication that the art is an offset print. This dot pattern looks like a more refined version of the technique used in comic book illustrations and newspaper photos.
Cornell University Library: Illustrated Book Study Resolution Samples
This site illustrates different printing techniques. The “Halftone Print” is an example of what an offset print looks like. The “structure sample” images in this illustrated guide to print techniques are particularly useful for identification.
In terms of value, offset prints don’t often have a strong resale, or auction, value, because they’re far removed from the artist’s hand. With the exception of contemporary prints, generally, an artist doesn’t originally choose the medium of offset printing; it merely serves as a way to reproduce or mass-produce an existing artwork. Because of this, an artist’s auction records don’t often play a role in the appraisal of offset prints – they are typically assigned a purely decorative value.
A basic rule of thumb for identifying an original print is to look for a visible pattern in the ink, as it serves as an indication that the art is a print. These patterns not only identify the work as a print, they help to identify the exact printing technique used by the artist.
Museum of Modern Art: What is a Print?
An animated tutorial to printing techniques
Washington Printmakers Gallery: Printing Techniques
Illustrated guide to print techniques
International Fine Prints Dealers Association: Learn About Prints
Click on “Collecting Prints”on home page.
Dutch University Institute for Art History Florence: Watermark Database
If a watermark appears on the print’s paper, this database can be used to place the paper both chronologically and geographically.
Bernstein Consortium: The Memory of Paper Database
A portal with links to 21 watermark databases and more than 205,000 watermarks.
Tate Gallery: Glossary
This page is a dictionary not only of artistic media, but also artistic movements, etc.
Identifying the artist of an unsigned work can be difficult, but there are often clues available to look for. For example, any stamps on the back of the canvas or the stretcher bars can potentially identify the supplier of those materials. This, in turn, can identify your painting’s country of origin, as well as place it in a rough time period. Additionally, some artists used only certain suppliers, and this information can be used by an expert to authenticate (or discredit) your painting as the work of a particular artist.
National Portrait Gallery: Artists’ Suppliers
A listing of artists’ suppliers in England from 1650-1939
Gallery, auction and exhibition labels on the backs of paintings can also yield new directions for research. Knowing where a piece was exhibited or auctioned can be useful, particularly if a catalog for that exhibit or auction exists. Sometimes even shipping labels still affixed to a painting hint at the origin of a painting, or perhaps its prior owners.
University of Santa Barbara: Arts Library Special Collections
UCSB is the UC systemwide repository for auction catalogs