Removing cardboard from paper.
I love to collect historical etches and gravures made near or in Arnhem, the town where I live. Yesterday, I received a wonderful small etching by an artist I have not yet deciphered. On it, a representation of “the Sabelspoort”, a medieval gate in the old historical city wall in Arnhem. The city wall was used to protect against all kinds of invasions and plunderers and had next to its many gates, four defensive towers, the Janspoort, the Velperpoort, the Rijnpoort and the Sabelspoort. Unfortunately the Sabelspoort is the only one of the gates that is still standing today. The other gates where long gone before the second world war and strangely enough the tower survived, standing fiercely while everything around it was shot to bits in the heavy fighting that took place during the war. Nowadays, the Sabelspoort is an official Dutch monument and has significant meaning and worth for Dutch architecture and Dutch history. So a nice asset to my modest collection!
The paper had some foxing and yellowing going on and when I removed the etch from the frame I noticed a sticker from the art dealer that framed this work, about 116 years ago. Notice the cool four digit phone number or “telephoon” as they would say back then. The framer and art dealer was J.B. Max who resided at 83, Steenstraat in Arnhem, about 1 mile away from where I live.
On a closer inspection I noticed that the etch was glued to a cardboard panel. This is always a big setback and when framed, you never know what to expect until the frame comes of. So in this case, a lot of unwanted cardboard and heaps of work! Its a Buddhist exercise gone crazy to maintain the concentration and determination needed to peal off the cardboard layer by layer. However there is really no choice, the cardboard has to come off to be able to stop further yellowing and foxing of the antique paper. The board is acidic and will propagate the existing problems in the paper.
I suppose it is a dirty job but someone has to do it! Before peeling, I first tested a few centimeters in the corners. For this job I used a Swann Norton surgical blade and tweezers. It turned out that the peeling was going amazingly well. the cardboard was very rich in wood fiber and therefore flaking easily, which made it easy to peel of the layers. The glue the framer used was probably something natural and starch based. There seemed to be no need for the use of solvents and liquids at this point, so I went for this plan:
- Removing the acidic backing board form the artwork with a Swann Norton surgical knife
- Sanding and scraping the paper to leave a smooth surface.
- Dry cleaning with rubbing gum on the front side of the etching
- Wet cleaning, removing acid with distilled water with added calcium hydroxide.
- Drying and pressing
- Mounting the etch on a piece of Kozo paper and with that creating a new and smooth backing.
It was time to begin peeling, chip by chip! The top layer of the etch paper was merged with the board and the glue that was used and came of spontaneously while removing the cardboard. These few millimeters were so rigid that they came off with the scalpel knife without too much effort, leaving a relatively clean surface without too much cardboard leftover residue. Because the job was tough on the paper thin blades, I used to two of them in the whole scraping and cutting process. One of them just broke in two pieces all together.
Next to blades, it cost me one big cut in my thumb because the Swann Nortons where pretty blunt at some point. And after about four hours of peeling away in intense concentration, the finish line came into sight while I was still attached to my fingers and the medieval Sabelspoort still had its towers.
When the peeling was done, I started removing all little specs of cardboard with a scraper. After this I was left with a very rough edged paper that didn’t look too good.
The front was left unaltered by the scraping and peeling work. I trimmed of the loose bits with scissors and started lightly sanding the paper.
After the sanding, the paper surface was much more smooth and it was time to finish up and get ready for the next steps of this cleaning up which I will post as soon as possible.
The end result looked pretty good. No changes where made to the visible side of the etching and the back can be used as is or can be mounted to a piece of Kozo paper which is acid free mulberry paper, almost invisible to the naked eye.