The short answer: offset printing is more cost-effective for large runs and digital printing works better for short runs. The longer answer: the difference lies in the technology used to print. Offset works by transferring ink from an etched plate to a rubber sheet which rolls the ink onto the paper. Digital doesn’t involve ink. Digital printing uses electrostatic rollers, called drums, to apply toner onto the paper. More significant set up is required for offset printing which is why digital is more cost effective for smaller runs.