North Korea announced yesterday that the corpse of former dictator Kim Jong-il will be placed on permanent display in Pyongyang. This seems to be standard practice for Communist nations—after all, Stalin, Ho Chi Minh, and Mao were all embalmed and set out for public display after their deaths, and Kim Jong-il’s body will be displayed in the same sprawling mausoleum as his father’s body. But how do they maintain the most famous preserved corpse of them all—the body of Lenin?

A 2010 book offers some helpful information. The decision to display Lenin’s body was made soon after his death in 1924, but within weeks authorities discovered that the Soviet leader’s facial muscles were decaying, altering his expression. To prevent further deterioration, specialists developed a chemical bath (the ingredients of which remained secret), and since then Lenin’s body has been dipped in that bath every 18 months. Of course, preserving a corpse for that long requires more than the occasional chemical bath: As an information sheet from Macalester College explains, the body also requires daily moisturizing, acetic acid injections (to remove dark spots on the skin), and a regular supply of new, specially-tailored suits. That last requirement has nothing to do with changing fashion trends; it’s just to protect against mildew.