West Africa Study Circle       

Documents relating to philatelic techniques

Extending the colour key
Extending the colour key describes a method devised by Ray Harris, and published by him in the London Philatelist, by which colour can be assessed more objectively than by eye, but which does not require access to a spectrometer.

Measuring cancel diameters accurately
Measuring cancel diameters describes a method for measuring the diameter of even partial cancellations very accurately. It which uses any photo-editing software which includes the facility to use layers allied to a transparency devised by Ray Harris which can be downloaded from the page