Login or Join Now

Upload your photos, chat, win prizes and much more

Username:
Password:
Remember Me

Can't Access your Account?

New to ePHOTOzine? Join ePHOTOzine for free!

Gum Bichromate

Join Now

Join ePHOTOzine, the friendliest photography community.

Upload photos, chat with photographers, win prizes and much more for free!

One of the most versatile Alternative Processes, Gum Bichromate was invented in 1855, and became popular at the turn of the century. The process takes advantage of the fact that colloids, such as gum, gelatine and glue, when mixed with a bichromate, become hardened and insoluble when exposed to light. By mixing a coloured pigment in with the colloid, and then washing away the undeveloped areas with water, you are left with an image in the dye. Exposure times using daylight will be typically between 30 seconds and 2 minutes. Advanced Gum Bichromate workers build up a number of layers of varied pigment colours by re-sensitising, re-exposing and re-developing prints.

Related Terms