The platinum and palladium print is considered by many to be the finest monochrome printing process. Platinum prints are capable of producing a long rich tonal scale, tremendous depth of shadows and the subtlest highlight details.

The platinum print is another iron sensitive process. Two sensitizing solutions and a platinum solutions are made:

The three solutions are mixed together just prior to coating. Different concentrations of the sensitizing solutions can be used to vary the contrast of the resulting emulsion.

The paper must be coated using a brush with no metallic surfaces (reacts with platinum). After drying the paper is exposed to ultraviolet light. The paper is developed in a solution of potassium oxalate. The image develops instantly so the print must be immersed in the developer instantly. The print is then cleared in three succesive baths of, for instance, hydrochloric acid clearing solution.

When the ferric salts are exposed to light, they reduce to the ferrous state. When the image is developed in pottassium oxalate, the platinum reduces to to the metallic state, where it has been exposed and in contact with the ferrous salts. The image is first formed by the iron and then by the platinum after development. Unexposed platinum and ferric salts are dissolved out. All traces of iron are removed by the clearing bath, leaving an image formed entirely of platinum.

Platinum prints are one of the most permanent printing media. The major disadvantage of platinum printing is the high cost. Palladium reacts almost exactly the same as platinum, and the two printing media are quite similar. Palladium prints are much warmer than platinum. The process details for palladium are almost identical, with a few minor changes. Palladium is substantially cheaper than platinum.