The most definitive method of determining whether a print is an original or a reproduction is by examination of its production process. All reproductions are made by a different process than originals; reproductions are photomechanically produced and originals are not. This difference in process can usually be spotted by an expert and in some cases is quite obvious.
- Most reproductions are made from a dot-matrix or half tone process, which produces a lentiginous image composed of a symmetrical pattern of small dots.. If you look through a fairly powerful magnifier (e.g. 10X) and you see little dots (either black & white or color), then you have a reproduction.
- If the print is supposed to be an intaglio print (engraving, etching, mezzotint, aquatint, etc.), then if there are big enough margins, a platemark should appear. Note that fake platemarks are not uncommon, but these usually differ in character from real platemarks. Also, the ink in an itaglio print will often feel raised from the surface, so if the print surface feels absolutely smooth, this is a clue that it is not an intaglio print.
- If the print is supposed to be a lithograph or woodcut or wood engraving, then there should be no platemark. If a platemark appears, you likely have a reproduction.
- Most intaglio prints, woodcut and wood engravings, when colored, are colored by hand with watercolors. If the color is printed and the print is supposed to be one of these types, then this is another clue you have a reproduction.
As a general rule, almost all prints and maps printed before 1800 are on laid paper and almost all prints and maps printed after 1800 are on wove paper.
- Laid paper is made by hand in a mold, where the wires used to support the paper pulp emboss their pattern into the paper. This pattern of closely spaced, crossing lines can be seen when the paper is held up to light. The first example of the use of wove paper in western printing was in 1757, so any print or map made before that should certainly be on laid paper. However, even in the second half of the eighteenth century, the use of wove paper was relatively rare, increasing in instances the closer to the end of the century. Also, some modern paper has false laid lines and reproductions often add false laid lines to make the item look more authentic. Thus the appearance of liad lines in the paper is a clue to authenticity, but not proof positive.
- Wove paper, in contrast, is made on a woven belt and lacks the laid lines. Thus the paper will lack the pattern of crossing lines when held up to the light. Though laid paper was used after 1800, the use of laid paper became less and less common as the nineteenth century progressed.
- Look for any printed information which indicates the print is a reproduction, e.g. “reproduced from” or a copyright notice, etc.
- The best way to tell what you have is to try to find a reference book which features the map or print you are trying to research. This can be a collection listing, an exhibition catalogue, or a or catalogue raisonné. These references often list details about the prints or maps and you can compare these to your print or map. Among the details to check are title, measurements and the exact wording of any imprint information. Note that old prints do vary a bit in size, but the measurements should be within about 1/4” of the recorded size.
- Many prints and maps were issued in bound volumes and if the item is large, then it will often have to have been folded to fit into the volume. This is especially true for old maps, where the majority of original antique maps from before the nineteenth century have a "centerfold." The appearance of a centerfold is often good evidence that you have an original.
Note that none of these tests are certain, for there are exceptions to all of them. Also, even if your print passes these tests this doesn’t mean that it is original, though failure of any indicates it probably is a reproduction. Ultimately the issue must be decided by knowing what process the print should be and knowing what the paper should be like. This often takes an expert to determine for certain.
You can read more about how to tell an original map in a "Tips of the Trade" article on the Antiques Roadshow web site.
You can read more about the different ways prints were made in the Antique Prints Blog posts on print processes.