Standard Negative Contrast Ranges for Palladium Prints
Na2 (Sodium Chloroplatinate) Method
| Mixture |
Negative Contrast |
Solution |
Drops |
| No. 1* |
Very Contrasty (1.85)
Palladium
Na2 (Sodium Chloroplatinate) |
A
Pd
2.5% |
6
6
1 |
| No. 2 |
Very Contrasty (1.75)
Palladium
Na2 |
A
Pd
5% |
6
6
1 |
| No. 3 |
Contrasty (1.60)
Palladium
Na2 |
A
Pd
10% |
6
6
1 |
| No. 4 |
High Medium (1.50)
Palladium
Na2 |
A
Pd
5% |
6
6
3 |
| No. 5 |
Medium (1.40)
Palladium
Na2 |
A
Pd
20% |
6
6
1 |
| No. 6 |
Low Medium (1.30)
Palladium
Na2 |
A
Pd
10% |
6
6
3 |
| No. 7 |
Thin (1.20)
Palladium
Na2 |
A
Pd
20% |
6
6
2 |
| No. 8 |
Very Thin (1.15-1.10
)
Palladium
Na2 |
A
Pd
20% |
6
6
3 |
Standard Negative Contrast Ranges for Palladium Prints. Na2 (Sodium Chloroplatinate) Method. * May Need One Drop of 3% Hydrogen Peroxide to prevent fogging.
Because the twelve-drop system is traditionally used in Pt and Pd printing, we have kept that format. Each supplement of Na2 is in addition to the twelve drops of coating (6 drops of Pd salt: 6 drops of ferric oxalate A). Note that ferric oxalate A contains no chlorate. Na2 concentrations of 2.5%, 5%, 10% and 20 % are used. The 5% and 10% are doubled in some cases to two drops per twelve to reach intermediate contrast ranges. For the greatest contrast, 20% is doubled or tripled to two or three drops per twelve of coating.
Standard Negative Contrast Ranges: The NA2 (Sodium Chloroplatinate) Method. Subject to revision. Copyright Dick Arentz ©2011.
|