Slipsheet

When a mimeoed fanzine is being printed, the wet ink on the newly printed sheet may smudge onto the back of the next sheet to be printed, making the printing look muddy. To prevent this, one can slipsheet, or insert by hand spare sheets of old paper (sometimes called crudsheets and often (dry) unneeded copies of other pages) between sheets as they are printed. Another word for this process is interleaving.