Under Construction, August 2011
1. BACKGROUND
Baskets are very common in Alaska, and are often used where ceramics might have been common in other cultures. Typically, baskets are made of plant materials such as spruce root, cedar bark, birch bark, or grasses. Archaeological basketry over 5,000 years old has also been found in waterlogged sites in Southeast Alaska, and several hundred years old on Kodiak Island.
2. POSSIBLE CAUSES
The most common white stuff we have seen on Alaskan baskets are dust, mold, adhesives, paint spatters, insect debris (such as cocoons) and PEG (polyethylene glycol.) Look with a magnifying glass to see how the white stuff is deposited. Powdery-looking spotty deposits may be mold. Dust would likely settle on certain areas that are horizontal, such as the lid if it has one or inside the base. The underside of the base may have accretions from adhesives, labels, or unclean shelves. Baskets were sometimes adhered onto an exhibit shelf in the old days to prevent them from moving with vibration of footsteps. Adhesives and repairs of various kinds have been used on baskets, so white stuff in association with a tear or loss is likely an adhesive. Waterlogged archaeological basketry was most commonly treated with a white glue in the 1960’s and 70’s, but since then polyethylene glycol treatments have been more typical. Too much high molecular weight PEG (PEG 3350 or PEG 4000 for example) will result in white deposits on the surface. These are soluble in warm water, and you can test this with a barely-damp cotton swab on the surface. There was a period of time when “feeding” baskets with oil was a popular maintenance technique. This sometimes appears as white haze on baskets, and may also make them brittle. Haze could also be a pesticide residue. Always be careful to wear gloves…not only are you protecting the baskets from substances on your hands, you are protecting yourself from whatever may be on the basket.
3. REFERENCES
Hartley, Emily. (1978) The Care and Feeding of Baskets. Self-published.
Ellen Carrlee’s notes: Coating mentioned is paraffin oil in mineral spirits, 16% solution, p 29. The author mentions that the techniques are derived from procedures developed by Bethune Gibson and Carolyn Rose of the Anthropology Conservation Lab of the Smithsonian’s Natural History Museum, and used there around 1974-75.
4. EXAMPLES IN ALASKA (click to enlarge images and see more info)