44th Annual Meeting – Textile Session, May 15, “Inherent Vice in the Woven Structure of Northwest Coast Spruce Root Hats” by Sara Serban

We all love the topic of inherent vice. And in this talk, the topic is presented as it relates to basketry, hats, and an exhibition at a museum of Canadian social history.
Sara Serban, Objects Conservator at the Musée McCord in Montreal, spoke about painted and woven spruce root hats she prepared for “Wearing our Identity: The First Peoples Collection,” a ‘permanent’ exhibition planned to last five years (with rotations). The five hats selected for display were made between 1850 and 1920 by weavers from the Northwest coast of Canada, including the Haida and Kwakwaka’wakw cultural groups. In her talk, Sara discussed how the hats’ materials, complex woven structure, past storage and environmental conditions, and previous treatments relate to current condition issues and present treatment challenges.
Sara consulted with Isabel Rorick, a talented Haida weaver (see some of her work here), in order gain a better understanding of the materials and techniques used to make these types of hats. Sitka spruce roots are used for weaving because they grow in long straight lines. Roots are usually 3 to 20 feet in length, but can be as long as 50 feet. After harvesting, the outer layer of bark is removed from the roots by heating with hot coals, causing the bark to peel, and then pulling the roots through a split stick. The root is then split lengthwise one or more times. The interior pithy core is discarded, the inner layer is used for the warp of the hat, and the outer polished layer is used for the weft.
The processed roots are soaked in water and then woven from the top down using a combination of two-and three-strand twining techniques. Three-strand twining is almost always used for added strength at the crown of the hat, and twill twining is used to create geometric patterns at the brim. Continuous warps are used in the beginning, with additional warps added in as needed. A wooden disk form can aid in shaping the hat during weaving. An awl is often used to push the stitches together, and when complete, the hats are watertight.
Sara reviewed condition issues and previous treatments of the hats chosen for exhibition. As can be expected, the older hats are more fragile, and they all have experienced deterioration from low humidity. Darkening of spruce root, from cream-colored to dark brown, as a result of oxidation is a condition issue I was not aware of and seeing this contrast surprised me (compare the historic hat in the image above with the light color of this contemporary spruce root hat made by Rorick). Sara pointed out that while woven spruce root baskets are stored resting on their bottoms, hats are usually stored resting on their brims, and this positioning may cause additional stresses within the hat structure over time. She also noticed that certain areas, like the top disc, top edge (or turn), and crown, are more susceptible to breakage.
The majority of hats had undergone previous treatments (sometimes multiple campaigns), and many of these interventions caused further damage to the root fibers. For example, one hat had been repaired with a thick, raffia-like fiber that caused overall distortions in shape and breakage of adjacent root fibers. Sara questioned whether this type of mending was a traditional repair carried out when the hat was in its source community, or if it was later work. After a survey of spruce root hats in the museum’s collection, she found many had similar repairs, and because of this consistency, the repairs were likely carried out in the museum.
The museum’s conservation records indicate that treatments using methyl cellulose, wheat starch paste, and mixtures of Lascaux 360 HV and 498 HV were carried out in the 1980’s. Additionally, Paraloid B-72 in acetone was previously used to repair at least one hat because wheat starch paste was not found to be strong enough, although it was noted that acetone did affect the black paint on the surface. The common basketry repair technique using twists of Japanese tissue coated in adhesive was found not to be reliable, as these repairs often failed (e.g. the tissue lifted) not long after they were applied.
Examination of these past treatments helped Sara plan her treatment approach. Since the hats did not respond well to the adhesive mends of the past, she created mechanical mends using hair silk to hold the sides of the breaks together.  She used a pattern of stitching with horizontal stitches on the outside of the hat and vertical stitches bridging the split on the interior. Prior to mending, she humidified distorted hats in a chamber with water and ethanol and then reshaped the hats, with the aid of carbon rod clamps (one of my favorite conservation tools). Tinted Japanese tissue, with twists to imitate weft strands, was used to fill losses on the hat’s crown. For loss compensation at the top turn of the hat, Sara first made molds of the woven surface using dental molding putty and then cast paper pulp into them. The paper fills were cut to shape, toned, and adhered with wheat starch paste.
After the presentation, an audience member asked about storage recommendations for the hats. Sara responded that ideally each hat would have a custom form with some type of cover that would offer protection from dust but not touch the surface of the hat.
This was one of several talks in the Textile Session that discussed more 3-D textiles (or textile “objects”), which were of particular interest to me as an objects conservator (see Muppets, Egungun,and a Digitally Printed Reproduction Sleeve). Also check out this blogpost about a related talk in the Objects Session: “The Aftermath of Meds: Removing Historic Fabric Tape from Tlingit Basketry” by Caitlin Mahony.