The Malde-Ware method, otherwise known as Print-Out Platinum-Palladium Printing, or the Ammonium Print-out was invented in the 1980s by Pradip Malde and Dr. Mike Ware. Their method related to the original ‘print-out’ platinum process of Giuseppe Pizzighelli from 1887 and employs a better-behaved iron sensitizer. Ammonium ferric oxalate is substituted for the notoriously unstable ferric oxalate. Further, ammonium salts of platinum and palladium are used rather than potassium salts yielding a higher degree of chemical solubility while also producing more hydroscopic surface when applied. While the emulsion can be pre-mixed from sensitizers and metals, these sensitizers are sold so that you can mix or inter-mix your own.