Full Extension
 
Medium:
Watercolour

Size: 
Original only available in large.   
Print versions available in small, medium and large.
 
Aperture: (visible painted surface inside mount)
Small          120mm x 170mm 5'' x 7''
Medium     147mm x 197mm 6'' x 8''
Large          204mm x 292mm 8'' x 12''

Frame surface area:
Small          253mm x 304mm 10'' x 12''
Medium    304mm x 354mm 12'' x 14''
Large         354mm x 455mm 14'' x 18''