Copper Corrosion

---------------------------------------------(this front ↑)


(with this back ↑)

18 September 2010 - Copper corrosion occurs in the presence of cupriferous inks (in blues and greens). This type of damage usually occurs in objects that have been colored in, such as maps and drawings. The slightest form of damage occurs as discolouration of the drawing. This discolouration passes from light green to black. Ink seepage to the adjacent pages can also occur - the chemicals can be transferred to the pages lying above or underneath, sometimes in the original color. That has not occurred in our Atlas yet. In a worst-case scenario, the areas affected by copper corrosion become brittle and actual holes appear in the paper. Luckily, that is also not the case here.

It is the green ink that causes the damage, for the primary cause is the cupriferous ink being used. As you can see on the back of the map, the copper ink is working its way through the paper. But many processes play a role in copper corrosion, including humidity and oxidation.
The process is irreversible, so climate control is crucial.

This map is of Nieuw Hoender Hoeck, a polder in what is now part of the municipality of Bernisse in the province of Zuidholland (near Rotterdam). I added a corresponding map from Google maps. That map has been turned 90 degrees to match the old map (So the West is top, and the town of Geervliet is in the top right hand corner in both the old and the new map). To enlarge, click on the picture.


The images of the Atlas der Neederlanden have been made by the in-house photographer of the Special Collections Department of the University Library of the University of Amsterdam.