Volume 10, Number 3, Sept 1988, pp.9-10

Technical Exchange

Chris Stavroudis, column editor


Tree-ring dating has been successfully applied to several European paintings at the Los Angeles County Museum of Art. The paintings were examined and the edges of the oak panels were sanded and polished to remove the varnish and reveal the individual tree-rings. The rings were counted and their widths were measured at least twice using a magnifying lens with a millimeter scale. The tree-ring measurements of the panels were graphed on semi-logarithmic paper and visually compared to each other. The ring widths were also entered into the computer for statistical comparison using correlation coefficient and Student's t-test. The tree-rings were assigned an absolute date by comparing them with several European reference chronologies. Because most of the sapwood was removed from the oak panels in the past to prevent insect attack, the felling year of the tree has to be estimated. Fortunately, oak has a predictable sapwood growth.

The European paintings dated so far using dendrochronology are from the 16th and 17th centuries. One painting, reportedly by Peter Paul Rubens, actually dates to 120 years later. The seven other paintings that were tree-ring dated were found to date to the active period of the assigned artist. Several more European Paintings on oak will be accurately dated by dendrochronology.

Molly Alexander
Conservation Research

Japanese Hand-Made Papers

Infusion Limited, Contemporary Japanese Crafts & Paper, supplies Japanese papers for conservation. The sample book is beautiful. The sample books and price lists are available and include information on the size of sheet, weight, pH, processing, and remarks on usage and fiber type. There is a 100 sheet minimum order.

Of special interest is the Hon-Mino-Gami line of paper:

Hon-Mino-Gami is an especially fine Washi paper made in the Mino region of Japan, near Nagoya. Kozo and Sayoko Furuta, specialists in making this paper, comprise the twelfth generation of a papermaking family. Their work is so representative of traditional Japanese papermaking that the Japanese government has named them a Living National Treasure.

Mino paper is made from a superior grade of mulberry bark which contains long fibers of uniformly excellent quality.... Paper made from this bark is fine enough for use in art conservation and elegant bookbinding. Its color almost never deteriorates, unlike that of ordinary wood-pulp paper.

Japan's spectacular modernization has not been without casualties, particularly among its traditional arts and crafts. Papermaking is no exception; it is currently in grave danger of extinction. It is our hope, not only to preserve papermaking as an art, but also to inspire new uses for traditional Japanese paper in present-day life.

The minimum order for the Hon-Mino-Gami is ten sheets. Infusion's head office is located at: 73 Cloud View Road, Sausalito, CA 94965, (415) 331-1850. Their Showroom is: Hankyu Inc., 7223 Melrose Avenue, Los Angeles, CA 90046, (213) 934-5489.

Conservation Materials, Ltd.

Doug Adams is evaluating two new products. One is the Art-Sorb cassette. About the size of a video cassette, this vented cardboard container comes with about 1-1/2 pounds of Art-Sorb beads (humidity conditioning material). It is considerably less expensive to use than the Gore-Tex Tile.

Also designed for control of the microenvironment inside a display case, potassium permanganate on alumina beads. The permanganate oxidizes organic pollutants inside the case to carbon dioxide and water vapor. The beads are generally placed in a polyethylene tray, out of contact with any other material in the case (especially activated carbon). The beads are self indicating, they change from purple to brown as the permanganate is reduced to manganese dioxide, and cannot be regenerated.

Train to Mediate and Arbitrate Disputes in the Arts

California Lawyers for the Arts (C.L.A.) is training mediators and arbitrators for problems arising in the Los Angeles arts community. Trained mediators and arbitrators will provide Alternative Dispute Resolution (A.D.R.) services to arts organizations and artists of all disciplines, volunteering their services for at least three cases per year. C.L.A. will offer A.D.R. services throughout Los Angeles County, in an effort to keep disputes out of the crowded court system.

The A.D.R. training program will take place on October 29-30, 1988, in Pasadena and will have approximately 35 participants. Tuition, which includes a training manual, will be $50 for artists and $150 for lawyers and others. A limited number of scholarships are available.

C.L.A., a non-profit service organization, is the only legal group in Los Angeles providing A.D.R. services to the arts community. The program, funded by Los Angeles County, is based on a model which C.L.A. has operated in San Francisco since 1980. The National Endowment for the Arts has selected C.L.A. to conduct A.D.R. training programs throughout the United States. If you are interested in training please write before September 20 to:

California Lawyers for the Arts
315 W. 9th St., 11th Floor Los Angeles, CA 90015

Course on the Conservation of Rock Art

Canberra College of Advanced Education is offering a one-year Graduate Diploma in the Conservation of Rock Art. The course, commencing in February, 1989, is a joint project of the Canberra College of Advanced Education and the Getty Conservation Institute.

The course is intended for applicants who posses a degree or equivalent, in a relevant field such as earth sciences, prehistory, anthropology or social sciences, conservation, rock art studies, or cultural or natural heritage management. Applications were due no later than 19 August 1988. Cultural Heritage Science Division Secretary, Canberra College of Advanced Education, P.O. Box 1, Belconnen, ACT 2616, Australia.


The 1989 Museum Management Institute is to be held 9 July to 4 August, 1989. The intensive, four-week training program in museum management and business practices is intended for mid- to senior- level staff from museums of all disciplines.

The MMI is one of seven operating entities of the J. Paul Getty Trust and is administered by the American Federation of Arts. For more information, contact: Ricki Lederman, Administrative Coordinator, American Federation of Arts, 270 Sutter Street, San Francisco, CA 94108, (415) 392-9222.

Big Sell Out

Before moving to Texas in October, I must clear out the contents of my private conservation business (formerly Torrance/van Gelder Conservation Studio). The business was started by my grandfather, who collected a lot of interesting, if not downright nifty, stuff. So we are talking about everything from hot table, air compressor, and dammar crystals, to Japanese prints, plaster busts, and paintings. Not to mention book shelves, light fixtures, solvents, frames, museum catalogues, etc., etc. Definitely something for everyone, and everything must go. The sale will be held on Saturday, October 1st and Sunday, October 2nd from about 9am until around 6pm at 128 1/2 Greenfield Avenue, San Anselmo, CA. I will be there sorting the stuff out the week before the sale, and can be reached then (probably evenings) at (415) 479-9500, or before September 16th at the Paintings Conservation Department of the J. Paul Getty Museum at (213) 459- 7611 ext. 349. Hope to see you there with a big truck real soon.

Mark van Gelder

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