What is the difference between masonite and hardboard?
They are the same thing. Masonite is a brand name of hardboard, although that company is no longer in business. Also, if you are familiar with the debate over types of hardboard, modern-day tempered masonite is not the same as old-fashioned tempered masonite, and is archivally sound if primed properly, just as with untempered masonite.