Fake News You Won't Want to Miss    by Eliane Dotson

People are always surprised when I tell them their map is a fake.  "But it's in a really old frame and it looks really old," they say.  "How can you tell?" they ask.  There are clues, and they are relatively easy to spot if you know what to look for on a map.  I always explain to them the clues, because my goal is to prevent reproductions from being offered on the market as originals.  It's not good for the map market. 
In my line of work, it is very common to come across fake maps (also known as "reproductions"), as I am constantly receiving email inquiries from people who want to consign material with us. More often than not they simply found the map at a yard sale or inherited it, they don't have any experience dealing with antique maps, and they are looking for my expertise.  However it is not very common for me to discover reproductions being passed off as originals by reputed auctioneers.  But it does happen, and here is one story.
I sat at my desk scrolling through dozens of maps in another auctioneer's sale, when I came across one that caught my eye.  A beautiful colored example of Hondius' double-hemisphere world map, Nova Totius Terrarum Orbis Geographica ac Hydrographica Tabula.  The first thing that jumped out at me was the auction estimate, which was a third of what this map usually sells for at auction.  I looked closely at the photos to see if there were any condition defects that would warrant such a low value, and it quickly became obvious. There wasn't anything wrong with the condition of the map, except that it was a reproduction, not an original copperplate engraving.  Yet the map was described as being from 1630, and even though the auction estimate was low, it was thousands of dollars more than one would pay for a reproduction.  Clearly whoever had catalogued this map hadn't realized it wasn't authentic.
Here are the clues that helped me determine the map was a reproduction:
CLUE 1. Absence of a plate mark. This is one of the first things I look for with copperplate maps, as most will show signs of a plate mark somewhere outside the engraving.  With 16th-17th century maps, the plate mark is usually very close to the outer neatline, as copper was an expensive material and therefore the plates were made as small as possible.  Checking for a plate mark isn't a foolproof method, as sometimes the sheet has been trimmed and the plate mark has been cut off, or the plate mark is very faint and indiscernible, or it can be concealed by matting within a frame.  On some counterfeit maps (those intended to deceive), the plate mark has been added by pressing a lightly-inked straight edge into the paper around the map.  The best way to identify whether a visible plate mark is authentic is to compare it with the plate mark of a known authentic example.  With few exceptions, a plate mark will maintain its shape and distance from the neatline on all examples printed from that plate.  You can find high resolution digital images of thousands of maps online to use as comparisons, including nearly 90,000 digital images in the archive on Old World Auctions.
What is a Plate Mark? The plate mark is the impression that the engraved plate made when pressed onto paper to print the map. The plate mark can usually be felt by touch as an indentation in the paper, and there is also often some grayish ink residue along the edge of the plate mark that shows the physical size and shape of the plate.
There were no discernible signs of a plate mark anywhere around the image of the Hondius world map, as seen in this photo.

CLUE 2. Quality of the engraved lines.  Copperplate maps are engraved using the intaglio method, which produces lines that are crisp, distinct and continuous.  Most modern printing techniques cannot replicate this aspect of an original engraving, resulting in lines that are slightly blurry, with closely engraved fine lines simply merging together.  This was particularly noticeable in the Hondius world map in question.  One caveat to this is that sometimes you will come across original engraved maps with poor impressions -- either the plate wasn't properly inked before being pressed onto the paper or the plate became worn down over time, causing the engraved lines to be less distinct.  Often these examples will still have some areas of the map that exhibit the crisp, continuous lines you should expect.  However if the entire impression is poor, other clues will have to guide your judgment on the authenticity of the map.

This example of an original copperplate engraving shows crisp, distinct, continuous lines.

This is the Hondius world map in question, in which the lines are indistinct, blurry, and have merged together in some places, particularly in the female figure's dress.

This original copperplate engraving shows how sometimes the impression isn't perfect and some areas are blurry, such as the female figure's dress, but other areas are still very crisp, such as the portrait at right.

CLUE 3. Paper quality. The quality and type of paper on which the map is printed is an important factor in confirming authenticity, but this is one of the clues that takes the most time and experience to master.  Until the late 18th century, the vast majority of maps were printed on handmade laid paper, which was made from linen and cotton rags.  The paper was made on a wire screen mold that created chain lines both horizontally and vertically on the paper, which can be seen if you hold a sheet of laid paper up to light.  Often shapes and names were added to the wire molds to create watermarks that identified the paper mill.  Specific watermarks are attributable to certain cartographers or publishers and can help date a piece of paper and identify its source.  People who handle lots of maps will come to know the attributes (such as thickness, color, and watermarks) of the paper commonly used by specific mapmakers.  Knowing these specifics helps experts ascertain whether the paper looks and "feels" right for a given map.  Of course this is one of the more difficult aspects to identify based on a photograph, so in-person inspection is typically necessary.
Laid paper is also characterized by a textured and uneven surface caused by irregularities in the linen/cotton and the hand-made process.  This factor can be more easily seen in a photo, and was the reason that I determined that the paper on the Hondius world map was not right for the 17th century.
This photo shows the back of the map, which is taped onto a piece of mat board. If you ignore the random spots of foxing and colored ink, you can see that although the paper seems to have some texture, overall the paper appears very uniform.  This consistency is indicative of modern papermaking techniques.  You can also see from this verso image that there is no plate mark or indentation where the plate would have been pressed down onto the paper.

CLUE 4. Absence of a centerfold.  Most folio-sized maps from the 16th-18th centuries will have a centerfold, which is due to the maps being folded in half vertically in order to fit into an atlas.  The centerfold is still visible even if a map has been removed from an atlas and pressed flat, and sometimes it is more visible on the back of the sheet than on the front.  It is also more common for there to be defects along the centerfold, such as separations, tears, creasing or toning.  However, not all maps were published in atlases, so knowing how a map was typically issued is essential.  Some maps were issued both in atlases and as separate sheets, and smaller maps may have been bound into a book or atlas along one side rather than the center of the map, so the absence of a centerfold may not always identify a reproduction.
The top two images show original copperplate engravings with evidence of a centerfold (and some tears and creases on the colored example).  The bottom image is the reproduction and doesn't show signs of a centerfold.

After noticing all four clues, I decided to contact the auctioneer to let them know that the map was a reproduction.  As I stated before, it is important to us at Old World Auctions that we help prevent fake maps from circulating the market as authentic originals.  Everyone makes mistakes, and we would want to know if we had made a mistake so that we could rectify the situation.  The auctioneer was very receptive to the information I provided and indicated that they would look into the situation further.  The auctioneer was not trying to deceive its customers -- it was simply an oversight.  (Please note that we are purposely keeping the auctioneer's identity private.)
There are a few key takeaways that I would like to share.  First of all, confirming authenticity and identifying reproductions takes effort.  Understanding what was common for a particular mapmaker or time period is critical.  This comes with experience, however in the absence of experience doing research will help.  There are reference materials that outline how specific maps were issued, common watermarks for certain mapmakers and time periods, and whether known forgeries exist and what signs to look for.  And comparing a suspicious map with a known original is always useful.
Second, the four clues listed above should not be considered in isolation.  Sometimes one clue is enough to identify a map as a reproduction, but one clue alone is not enough to confirm authenticity with certainty.  One must consider all of these factors together. 
Third, this guideline is primarily intended for copper and steel plate engravings.  For other types of printed maps, such as woodblock, woodcut, or lithographs, the clues must be slightly modified.  And sometimes, comparing the map in question with an original is the only way to verify authenticity.  In these cases, you will need to compare the size of the image, printing style, paper quality, absence or appearance of folds, and if printed in color, the colors used and saturation of color.  Again, experience helps, so the more maps you encounter, the better your eyes will be at spotting inconsistencies.
And finally, buyer beware!  If you are not buying maps from a business that specializes in maps, you will have to put in extra time and effort to do your homework.  Make sure you inspect the map in person, or at least request photos of both the front and back of the map.  Be especially cautious of maps in frames, as frames are notorious for hiding key tell-tale signs that a map is not an original.  And if you encounter an auctioneer that states that all items are sold "as is" and that no guarantees are made regarding the accuracy of their statements or the authenticity of their offerings, that should be a red flag.
In our experience, it is much more common to encounter reproductions that are relatively easy to identify, rather than counterfeit maps that were created with the intent to deceive.  The fact that any of them exist requires everyone to remain vigilant in closely inspecting each map, and checking for the four clues above is a good guideline.  At Old World Auctions we take authenticity very seriously, and we hope that by sharing our expertise, you too can help us in our quest to keep fake maps out of the marketplace.