What materials are used for The Currency Frame?

The outer frame is made of aluminium. The passe-partout is made by KLUG-Conservation, constructed from 100% bleached cellulose. It is free of wooden fibres, lignin-free and acid-free. It has a scratch-resistant coated plexiglass panels with UV protection. The back of the frame is made from welded steel, with felt gliders attached to provide a smoother fit to the wall.