opacity: Renegade Craft Fair Holiday hallway
opacity: Art Institute of Chicago - detail from Self-Portrait by Vincent van Gogh, 1887 painting, oil on artist's board.jpg
opacity: lion 3 - Lincoln Park Zoo, Chicago.jpg
opacity: by Tim Etchells
opacity: Field Museum - Eocene spiny-finned fish eating herring - Mioplosus labracoides and Knightia eocaena.jpg
opacity: Sue the T Rex
opacity: Calder's Flamingo reflection in windows of Loop Station Post Office.jpg
opacity: by Steve Lambert
opacity: Eurasian lynx 1 - Lincoln Park Zoo, Chicago.jpg
opacity: averaged window series via dubster's average tool
opacity: Snow and ice in an underground train station
opacity: Art Institute - detail from Madame Paul Escudier (Louise Lefevre) by John Singer Sargeant, 1882.jpg
opacity: Tiffany stained glass angel wing
opacity: Field Museum - Tiffany window, Grainger Hall of Gems (detail).jpg
opacity: Field Museum - Eocene gar fin detail - Masillosteus janei.jpg
opacity: Art Institute of Chicago - face detail from Male Figure from the Tavern Club by Lora Marx, 333 North Michigan Avenue, Chicago, c. 1937.jpg
opacity: street headphones in the Loop.jpg
opacity: Way-#latergram from pre-#heweb13.
opacity: Field Museum - trilobite - Cybele pander - found in St. Petersburg, Russia.jpg
opacity: Art Institute of Chicago - face detail from thunderbolt deity Shukongojin, Japan, 12th-14th century, wood with traces of polychromy.jpg
opacity: Field Museum - Permian amphibian - primitive tetrapod - Cacops aspidephorus - Oklahoma.jpg
opacity: Art Institute of Chicago - detail of Shiva from bronze Shiva and Uma Seated with their son Skanda (Somaskanda), India, Tamil Nadu, Vijayangar period, c. 1400.jpg
opacity: Art Institute of Chicago - Greco-Egyptian octadrachm (coin) portraying Arsinoe II, issued by Ptolemy II, 261 BC.jpg
opacity: Field Museum - Permian - Sphenacodontid synapsid - Sphenacodon ferox - New Mexico.jpg