Restoring XK140 sidescreens

Restoring a pair of XK140 roadster sidescreens. The upholstery shop will not use plexiglass replacement windows as they crack. They will use LEXAN. Anyone know of a supplier/manufacturer for lexan,or comparable, sidescreen windows?


LEXAN is a trade name for Polycarbonate a.k.a. PC. There are various/many suppliers of PC sheet around the world. Lexan had been developed by GE Plastics in the 1970s but no longer manufactures plastics as it has been taken over by a different group. LEXAN is still often used as a “generic” name for Polycarbonate. In Europe Makrolon is another trade name for PC.
The advantage of Polycarbonate over Acrylic (or PMMA and originally better known as Perspex (UK) Plexiglass (Germany) or Lucite (USA)) is its strength: it is very flexible and has a very high impact resistance.

The risk of braking PMMA when cutting it to size, is far bigger than when using PC (which is probably the reason for your shop to go for PC).

The disadvantage of PC is its poor UV resistance (with yellowing as a result). If you decide for PC, try to find a PC that has been coated with a UV resistant layer. It will enhance the life of your PC side screens.

Both PC and PMMA are available from various sources and in various thicknesses.

Bob K.


I have seen one side curtain with a manufacturers name stamped into the clear plastic.
This subject also applies to rear windows in most XK120 roadsters and 120DHC’s