What is the plastic stool in a pizza box for?
The plastic stool, dubbed the 'pizza saver'(sometimes referred to as pizza table, pizza stool, pizza bone, pizza chair, pizza lofter, package saver, or pizza ottoman), isn't for decoration or to keep the slices together, but actually separates the pizza box's lid from the meal's toppings - so they don't end up stuck disastrously to the top. ... The deceptively simple idea of the 'package saver'got a patent in 1985.
The frustrating mess is caused by the condensation from the hot, steaming pizza which makes the lid sag - and melt into the sticky cheese and toppings.