Plate 632 sets a ridden horse through a full sequence, the rider's posture shifting frame by frame with the animal beneath. Muybridge rarely stopped at the horse alone — adding a rider let the plates settle a second argument, how a body in the saddle actually moves with the gait rather than how artists had assumed it did. The rider's seat rising and falling out of sync with the horse's back, two motions in one frame. The camera caught the rider still learning the horse's arithmetic.

Maker: Eadweard Muybridge, collotype
Date: 1887
Medium of the original: Painting
Original held by: University of Pennsylvania / DPLA
Credit: University of Pennsylvania / DPLA
Rights: Cleared for print
Catalogue number: PA-00113

As chosen: 20 x 16 in, art print, classic frame
Picture	20 x 16 in
Outside size	21.6 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
10 x 8 in	300	Excellent	Trimmed 1%
14 x 11 in	216	Excellent	Trimmed 0.8%
16 x 12 in	189	Good	Trimmed 5.3%
20 x 16 in	150	Good	Trimmed 1%

Sizes withheld
Size	Why
12 x 8 in	Wrong shape: a 16% crop
18 x 12 in	Wrong shape: a 16% crop
24 x 16 in	Wrong shape: a 16% crop
24 x 18 in	126 dpi; a historical scan is never enlarged
30 x 20 in	Wrong shape: a 16% crop
30 x 24 in	100 dpi; a historical scan is never enlarged
36 x 24 in	Wrong shape: a 16% crop
40 x 30 in	75 dpi; a historical scan is never enlarged
48 x 36 in	63 dpi; a historical scan is never enlarged
60 x 40 in	Wrong shape: a 16% crop