I am working with pure palladium and in 30 years I have never meet black point. Perhaps because I am working with a stock of old paper before 1985
Excuse my poor english
I pratice photographraphy fom 30 years, ans palladium printing from 20 years. We can find my pictures in Nicephora Niepce Museum in chalon sur saone, fox talbot museum Lacock Abbey, and Musee der la photographie de Lausanne.