Art Conservation: Supplementary Material

This post contains supplementary material and/or clippings from my article about permanence of artists materials, published in the May 2007 issue of the CARFAC Saskatchewan Visual Artists Newsletter. That post can be found here: http://edpas.net/303/. I was originally planning to include information about conservation issues with digital printmaking, but that will have to wait for a future post.

My Background as it Applies to Conservation

My awareness of conservation issues in art started fairly early on in my career. I trained as a printmaker and throughout my studies in this field there was a strong emphasis on using high quality materials of the greatest known longevity. In addition to traditional printmaking process, my practice has included wood and painted wood sculpture, painting with various materials on various supports, a number of mixed media techniques, and digital media. I’m also a bit of a materials junkie and tend to do a fair bit of research about processes and techniques.

About the Workshop

The workshop given by Canadian Conservation Institute staff was held over two full days in March 2007. Each day was split between paintings and works on paper. The mornings were lectures and discussions about paintings and what can go wrong with them, and the afternoons were devoted to works on paper. While there was a small amount of hands-on work in the sessions about paintings, and some discussion of actual paintings brought by the workshop attendees, we did more hands-on activities in the works-on-paper sessions. The activities included:

  • Framing works on canvas: we were given pieces of frame, stretcher bar, backing boards, and various pieces of hardware, and were shown how to put them together in a conservationally-recommended way
  • How to make wheat starch paste, an adhesive that is commonly used by conservators because it is versatile and easily reversible
  • How to mat works on paper: we learned a number of methods of attaching works on paper to backing mats, including traditional bar-and-t hinges, as well as a couple of ways of making archivally-sound mounting corners.
  • Testing lightfastness: we made our own test strips of a number of different inks, some of which are known to be fugitive, and other which are known to be resistant to fading. We were expected to put the samples in a window for a long period of time to see which colours last. My sample swatches are still in a pile of papers in my studio, though.
  • Testing for acidity: we were shown how to test the pH (acidity/alkalinity) of paper by using pH strips and an acidity-detector pen
  • Testing for lignin: Lignin is usually present in papers made from wood fibre. It can break down into acidic compounds. We tested a number of papers for lignin content using a pen designed for this. Unfortunately, the pen is no longer on the market.
  • Sherry Guild gave a demonstration of the Beilstein test for chlorinated plastics. I’m still not completely clear on why—from an art conservator’s perspective—PVC plastic is evil, but it has something to do with the possibility of the chlorine in the plastic degrading into an acidic compound. The Beilstein test requires a clean-burning flame, a copper wire, and a small pieces of the plastic to be tested. For the demonstration, Sherry used a small butane craft torch similar to what I’ve seen in professional kitchens for making crème brulé. In addition to the test tools, appropriate ventilation and safety equipment are always a good idea. I won’t go into detail here, but the process involves observing the colour of the flame when you burn the plastic in the presence of copper.

Materials Testing

Most testing of materials is what the industry calls “accellerated testing” whereby a material is subjected to extreme circumstances for a short period of time in order to simulate moderate circumstances over a long period of time. This is much like what we see in kitchen hardware testing labs where a mechanical device opens and closes a fridge door nonstop for days at a time in order to see how the door will break, and when.