If you ever wondered how iconic characters like Popeye the Sailor Man or Betty Boop were created, here’s your chance to know. Fleischer Studios’ internal production reference guide is now available to download for free from archive.org. This snippet of history offers some insight into how 2D animation was produced eighty years ago, and while there have been technological changes, it’s remarkable how much has stayed the same. The Fleischer cartoons contrasted Disney’s bright and colorful style in the 1930s before the studio was taken over by Paramount Pictures in 1942.