What are the components used to make jaccuzzi covers. Especially the white material inside the leather cover.?

Answer 1

They are made from a (usually) 2 piece plywood base, joined by a couple of pieces of piano hinge. The inner core is styrofoam and the covering is upholstery fabric, (usually vinyl) similar to cheap car seats.

Answer 2

The white material is Styrofoam, which is a trademark name for closed cell extruded polystyrene used for building products and many other applications. However, coffee cups and white foam food containers are not Styrofoam, as Dow points out in their website.