Procedure

1. Coat a specific brand of semi-gloss photo-paper with a solution of the dye thionin acetate.
2. To then readily convert that thionin acetate coating into the less soluble salt thionin ferricyanide.
3. To then coat the sheet with a special photosensitizing liquid we have developed.
4. To then expose the covered sheet to the image from a projector.
5. To then develop the exposed sheet in acidic ferrous sulphate solution where it creates the famous Prussian Blue pigment and removes thionin dye.

Blyth, J. & Richardson, M. De Montfort University, The Gateway, Leicester, LE1 9BH

Non-holographic imaging systems