Gerardus Mercator solved a problem that had defeated everyone: how to flatten a round world so a ship's compass course would draw as a straight line. His 1569 projection stretched the poles toward infinity — Greenland swelling to the size of Africa — but a navigator could at last rule a line and sail it. Five centuries on, it is still the map on your phone. The chart that made the ocean crossable, and quietly reshaped how the whole world pictures itself.

Maker: Gerardus Mercator
Date: 1569
Medium of the original: Plate
Original held by: Published Duisburg
Credit: Published Duisburg
Rights: Public domain, verified
Catalogue number: PA-00314

As chosen: 24 x 16 in, art print, classic frame
Picture	24 x 16 in
Outside size	25.6 x 17.6 in
Depth	0.9 in (22 mm)
Weight	[[REAL PROOF NEEDED: shipped weight per size and frame]]
Hanging	[[REAL PROOF NEEDED: hanging hardware Prodigi fits to this frame]]
Material	Enhanced matte art paper, 200 gsm; acrylic glazing
Made in	Charlotte, North Carolina, by Prodigi

Before a size goes on sale, the file is measured against it: pixels per inch at that size, how much of the picture a crop would lose, tone and sharpness. A size that fails is not offered, so there is nothing to choose wrong.

How the print check works

Sizes offered
Size	dpi	Grade	How it fits
12 x 8 in	431	Excellent	Trimmed 4.7%
18 x 12 in	287	Excellent	Trimmed 4.7%
24 x 16 in	215	Excellent	Trimmed 4.7%
30 x 20 in	172	Good	Trimmed 4.7%

Sizes withheld
Size	Why
10 x 8 in	Wrong shape: a 21% crop
14 x 11 in	Wrong shape: a 19% crop
16 x 12 in	Wrong shape: a 15% crop
20 x 16 in	Wrong shape: a 21% crop
24 x 18 in	Wrong shape: a 15% crop
30 x 24 in	Wrong shape: a 21% crop
36 x 24 in	143 dpi; a historical scan is never enlarged
40 x 30 in	Wrong shape: a 15% crop
48 x 36 in	Wrong shape: a 15% crop
60 x 40 in	86 dpi; a historical scan is never enlarged