Figure 3 from: Diazgranados M, Funk V (2013) Utility of QR codes in biological collections. PhytoKeys 25: 21-34. https://doi.org/10.3897/phytokeys.25.5175

Figure 3 - QR code size (side) vs. information for the four levels of error correction (L (purple line): 7% of tolerance; M (green line): 15%; Q (blue line): 25%; and H (red line): 30%). Below the lines QR codes are unreadable by most scanners; above the lines they are all readable.
Encoded text (including returns):
- 111 characters:
"Photographs: http://collections.mnh.si.edu/search/botany/search.php?action=10&irn=10076557&width=495&height=640"
- 219 characters:
"US National Herbarium
Montanoa josei V.A. Funk (Asteraceae)
US Sheet No.: 2325539 | Barcode: 00128657
Specimen photographs: http://collections.mnh.si.edu/search/botany/search.php?action=10&irn=10076557&width=495&height=640"
- 406 characters:
"US National Herbarium
Montanoa josei V.A. Funk (Asteraceae)
Collection: Cuatrecasas, J., Romero Castañeda, R.; 24768; Holotype; 1959-10-10; Colombia; Magdalena; Sierra Nevada de Santa Marta, Hoya del Rio Donachui, Cancurua. Elevation: 2400-2650 m.
US Sheet No.: 2325539 | Barcode: 00128657
Specimen photographs: http://collections.mnh.si.edu/search/botany/search.php?action=10&irn=10076557&width=495&height=640"
- 568 characters:
"Smithsonian Institution
National Museum of Natural History
US National Herbarium
Montanoa josei V.A. Funk
Family: Asteraceae
Collection: Cuatrecasas, J., Romero Castañeda, R.; 24768; Holotype; 1959-10-10; Colombia; Magdalena; Sierra Nevada de Santa Marta, Hoya del Rio Donachui, Cancurua.
Elevation: 2400-2650 m
Verification: Original publication and alleged type specimen examined
US Sheet No.: 2325539
Barcode: 00128657
Specimen photographs: http://collections.mnh.si.edu/search/botany/search.php?action=10&irn=10076557&width=495&height=640
Copyright © Smithsonian Institution".