Operating procedure

Prepare a silver diamine solution:
- Gradually add ammonia to the silver nitrate solution:
* until the solution turns black
* continue gently until the solution becomes transparent again

Float the sheet upside down on the saline solution for 2 minutes
Leave to dry for 30 minutes.

Under UV light, coat the sheet with the silver diamine solution.
Leave to dry in the shade.

Expose (6 minutes).
Wash for 60+60 seconds.
KBr solution bath, 2 minutes.
Wash for 30+30 seconds.
Fixer bath, 30 seconds.
Wash for 30+30+30 seconds.
Dry.

This method is more complicated than the one usually found, and I am almost certain that this second NaCl bath only soils the white paper.