Dr. Pratt’s developer

In a previous post – you can see it here – I mentioned Dr. Pratt’s developer in passing. A web search for it yields no results. I’d like to give the formula and instructions for its use here, so that it becomes part of the collective cyber-consciousness.

Dr. Pratt’s developer is a two-solution paper developer used to achieve different contrast levels with non-variable contrast papers. I got this information from Pirkle Jones in 1988.

The first solution, called Part A, or the soft solution, is made by mixing together the following:

• Water – 3 L
• Metol – 50 g
• Sodium sulfite – 180 g
• Sodium carbonate – 120 g
• Potassium bromide – 7 1/2 g

After you mix everything up, add water to make 4 liters.

The second solution, called Part B, or the contrasty solution, is made by mixing together the following:

• Water – 3 L
• Hydroquinone – 50 g
• Sodium sulfite – 180 g
• Sodium carbonate – 330 g
• Potassium bromide – 30 g

After you mix everything up, add water to make 4 liters.

Starting with number two paper, here are the mixtures to get approximate paper grades between one and four:

• 1 – 8 parts A, no B, 8 parts water
• 1 1/2 – 7 parts A, 1 part B, 8 parts water
• 2 – 6 parts A, 2 parts B, 8 parts water
• 2 1/2 – 5 parts A, 3 parts B, 8 parts water
• 3 – 4 parts A, 4 parts B, 8 parts water
• 3 1/2 – 3 parts A, 5 parts B, 8 parts water
• 4 – 2 parts A, 14 parts B, no water