My grandfather used photostats for a multitude of purposes. Getting his original artwork back from a publisher was not always easy and sometimes downright impossible. Jack needed to have access to his art so he knew what previous plotlines were covered, what costumes he had used and even what characters were in a certain story. When it became obvious that artwork would not be returned, my grandfather turned to photostats.
These photostats were usually one-of-a-kind copies that my grandfather kept. The above stat from Fantastic Four #96 used very small paper and Jack kept it in booklet form. You can see Jack's dialogue notes and plotting in the margins.
Some Large, Some Small: Most of the Marvel and DC stats measure about 12/18. Sadly most of the 1960s stats disintegrated over time and very few are left. The stats from the 1970's are in much better shape. These include copies of the inked artwork, as well as uninked and even unused versions of comic pages. Our last example of stats that you will see, include animation art from the 1980s. These huge stats feature some amazing concepts that my grandfather did for animation and even include a few surprises like The Phantom, Super Powers, Wonder Woman and Mr. T.