Textile conservators are responsible for a large collection of approximately 20,000 objects including window treatments, bed curtains, rugs, costumes, quilts and coverlets, needlework and upholstery. Damage to textiles comes from many sources including unstable environmental conditions that cause mold and staining from high humidity and exposure to excessive light that weakens and discolors textile fibers and fades dyes and colorants. When abrasive, acidic soil from the environment becomes embedded in the fibers it weakens and disfigures the textile. Stains and wear from past usage also contribute to deterioration. Some dyes and finishes used in the production of textiles are inherently unstable and may case serious damage. Textile conservators support and stabilize the structure of textiles while reducing stains and degradation where ever possible.
Winterthur's textiles are stored in stable environmental conditions using acid-free archival quality tissues, boxes, and fabrics. To prevent creases which cause localized damage to the fibers, textiles are rolled or padded with acid-fre tissue. Textiles on open exhibit are cleaned regularly by careful low-suction vacuuming to remove environmental dust. Lighting specialists are particularly vigilant in lighting textiles and keep the levels very low. If a textile becomes too weak to remain on exhibit, it is retired to the study collection and replaced with a textile in better condition or a reproduction fabric. For upholstered furniture, textile conservators work with furniture conservators to preserve existing fabrics or replace them with reproductions.
A Damaging Drip
A side chair (1957.518.4) made in Boston about 1800 had the misfortune of being under a drip from a slow leak in an air handler on the floor above. The leak severely stained the striped silk and cotton upholstery fabric. The fabric, woven in the late 18th century, is not original to the chair but was installed as the show fabric at a time when common practice involved tacking it directly to the seat rail. To avoid causing additional damage to the seat rail, the textile was treated without removing it from the chair.
The leak caused both staining and a "tide line" on the seat fabric. Tide lines occur when contaminants in the water and soluble degradation products in the fabric and upholstery padding are pulled along the fabric by wicking or capillary action to a point where evaporation takes place. The contaminants and degradation products are left behind forming a tide line that disfigures and weakens the textile. The damaged area may also become quite stiff and this inability to flex and move with the rest of the textile can cause additional damage.
After photo documentation the stained area was tested with a small amount of purified water applied with a fine brush. The stain was quite soluble in water and readily absorbed by blotter paper. Further testing confirmed that the dyes in the fabric are not water soluble and will not run.
To treat the fabric, a conservator brushed water on a small area of staining and then lightly pressed blotter paper against the area to wick up discoloration. The amount of water was carefully controlled to avoid solublizing contaminants from the upholstery padding below the fabric. This process continued until the blotter no longer picked up significant staining. At that point, the area was was moistened again and a dry purified cellulose pulp was tamped into position and, using capillary action, left to wick up the remaining stain. As the pulp dried, it pulled out any remaining soluble discoloration from the fabric. A faint stain remains in the fabric, but the damaging and disfiguring tide-line and contaminants are gone.
Top Image: (Left) Stains are absorbed into blotter and cellulose pulp. (Center) Cellulose pulp has absorbed stains from the chair upholstery. (Right) Chair seat after stain reduction.