What is a collodion wet plate?

The Wet Collodion process was invented in 1851 by an Englishman named Frederick Scott Archer. It was an answer to Talbot's paper negative, the Calotype (1839), and the Daguerreotype (1839) from Louis Daguerre (a silver coated copper plate fumed with iodine and bromine and developed over hot Mercury). The paper negative printed on Salt paper was "soft" but reproducible and the Daguerreotype was sharp and highly detailed, but it was a "one-off" and not reproducible. The Wet Collodion process produced a sharp, highly detailed negative and it was also reproducible - printed on Albumen and Salt paper.

The steps of making a Wet Collodion image:

1. Cut a piece of glass and de-burr or de-sharpen the edges

2. Clean the glass very well.

3. Flow Collodion onto the plate (this Collodion contains two salts; an iodide and bromide. It also has additional alcohol and ether.

4. Sensitize the plate in silver nitrate for 3 - 5 minutes.

5. Expose the plate in the camera.

6. Develop the plate with an iron base developer - this developer contains distilled water, alcohol, acetic acid and iron.

7. Fix the image in KCN or Sodium ThiOSulfate.

8. Varnish the image with Gum Sandarac, alcohol and lavender oil.

9. Let the varnish cure and et voile! A Wet Plate Collodion image.

Post Script: The Wet Collodion process can produce both Negatives and Direct Positives. The process is basically the same.