Collotype printing is a planographic technique, with prints taken from a gelatine matrix. It is carried out by exposing a negative image onto the light-sensitised gelatine, with greater light exposure encouraging the gelatine to harden and promoting the development of broader and more frequent cracks.

What is the Collotype process?

Collotype is a photomechanical flat printing process used to produce varying tones and shades. The process involves coating a glass plate in a gelatin solution, and over that a light-sensitive dichromate gelatin, which is left to dry at around 50 degrees celcius.

How do you make a Collotype print?

In the process, a plate (aluminum, glass, cellophane, etc.) is coated with a light-sensitive gelatin solution and exposed to light through a photographic negative. The gelatin is hardened in exposed areas and is then soaked in glycerin, which is absorbed most in the non-hardened areas.