DISCLAIMER: Processing must be done with thoroughly cleaned glassware and mixing utensils. Use non-metallic forceps or tongs without serrated edges to handle and transfer item(s) from processing trays.

Tray 1 (Pre-Rinse Solution)

1. Remove previously applied chemicals (e.g. DFO, ninhydrin, etc) or debris from the item’s surface.

2. Place distilled water in a thoroughly cleaned glass tray (large enough to accommodate item without folding).

3. Submerge item for 5 – 10 minutes, gently rocking the solution back and forth across the item.

Tray 2 (Maleic Acid Prewash Solution)

4. Combine the following prewash solution in a beaker with a magnetic follower. Place the beaker on a magnetic stir plate until the maleic acid has dissolved. 

25g Maleic acid

1000mL Distilled Water

5. Place solution in a thoroughly cleaned glass tray (large enough to accommodate item without folding).

6. Submerge item for 5 – 10 minutes*, gently rocking the solution back and forth across the item. 

*NOTE: If item begins to emit bubbles, leave the item submerged in the solution until bubbling ceases.

Tray 3 (Physical Developer Working Solution)

7. Combine the following Redox solution in a beaker with a magnetic follower. Place the beaker on a magnetic stir plate until the solids have dissolved.

30g Ferric Nitrate

80g Ferrous Ammonium Sulfate

20g Citric Acid

1000mL Distilled Water

8. Combine the following Detergent solution in a beaker with a magnetic follower. Place the beaker on a magnetic stir plate until the solids have dissolved.

3g n-Dodecylamine Acetate

4g Synperonic-N

1000mL distilled water

9. Combine the following Silver Nitrate solution in a beaker with a magnetic follower. Place the beaker on a magnetic stir plate until the solids have dissolved.

200g Silver Nitrate

1000mL distilled water

10. Combine the following (in the order listed) immediately prior to use to produce the Physical Developer Working Solution. Place the Redox solution in a beaker with a magnetic follower, then add Detergent and Silver Nitrate solutions. Place the beaker on a magnetic stir plate and stir for 3 – 5 minutes.

1000mL Redox Solution

40mL Detergent Solution

50mL Silver Nitrate Solution

11. Place solution in a thoroughly cleaned glass tray (large enough to accommodate item without folding).

12. Submerge item for 5 – 15 minutes, gently rocking the solution back and forth across the item. Periodically inspect item to prevent overdevelopment of ridge detail.

13. Replace solution as necessary. Discard if solution becomes badly contaminated with debris or dark gray silver particles are observed floating on the surface or bottom of tray. 

Tray 4 (Post-Rinse Solution)

14. Rinse item before drying out from Physical Developer Working Solution, causing the item to become brittle. 

15. Place distilled water OR tap water in a thoroughly cleaned glass tray (large enough to accommodate item without folding).

16. Submerge item for 3 – 5 minutes, gently rocking the solution back and forth across the item.

17. Allow item to air dry completely. A hot air dryer may be used to expedite the drying process. 

18. Ridges will develop a grey color. 

19. Capture ridge detail using 1:1 photography.