A Printer allows you to copy enchanted books and written books when powered by a Ink Cartridge or Ink Sacs, one Ink Cartridge lasts ten times longer than an Ink Sac.
Putting an Ink Cartridge or Ink Sac into the left slot will fuel the printer, putting an enchanted book or written book into the top slot will start the copying process if there's fuel, then the red copy-progress bar will begin to rise (the black ink bar will recede at a certain speed, depending on which type of ink you used).
After the red bar fills up, your copied item is placed in the bottom slot. Enchanted books take much longer to copy as compared to written books. Make sure to put enough Ink Cartridges or Ink Sacs in, as progress will start dropping down if the printer runs out of fuel.
The crafting recipe is 5 Stone , 2 Block of Iron, 1 Paper and 1 Redstone to create a printer. Place a stone on the top left and right of the crafting menu, a paper in the top middle, an iron block on the middle left and right, redstone dust in the exact middle, and 3 stone across the bottom.