Original Superman drawings by: his co-creator, Joe Shuster (image 1); Silver Agers Curt Swan and Wayne Boring (images 2 and 3, respectively); and John Byrne, who took up the character in the 1980s (image 4).
Collection of after-work sketches from a couple of weeks ago. Hal there looks like Robin as Green Lantern because I originally started them as their manga incarnations. Justice League has got one now! (art done by Shiori Teshirogi and I think the first chapter’s out in Japan).