Keith Schreiber posted on FB on August 10, 2017:
we really don't want the final clearing bath to be acidic since that would leave the paper in an acidic condition.
Because of that, tetrasodium EDTA is best for the final bath.
The best practice is probably to follow the full Mike Ware / Pradip Malde regime as follows:
1. EDTA disodium salt (~ 50g + 1 liter water), 10 minutes [exhaustion: use until yellow-brown]
2. freshwater rinse, 1 minute
3. Sodium metabisulfite (hypo clearing agent, ~ 25g + 1 liter water), 15 minutes (greater concentration is not critical) [exhaustion: use until very light yellow]
4. freshwater rinse, 1 minute
5. EDTA tetrasodium salt (~ 50g + 1 liter water), 15 minutes [exhaustion: use it begins to discolor]
6. freshwater rinse, 1 minute
7. Wash 20-30 min
notez qu'il n'y a pas de rincage avant le bain 1.