Progress in strain monitoring of tapestries

Tapestries are an important feature of many historic house and museum collections. They are often displayed on walls as originally intended, either hanging from the top edge or attached around all four edges. Textile conservators are experienced in visually assessing textiles for evidence of damage. Condition assessment by visual inspection is now routine (Lennard 2006). However, such visual inspection does not allow quantification of the strain imposed by the textile’s own weight. Tapestries, like other textiles, experience deformation under load which is presumed to be a significant factor in their deterioration. Although there has been some interesting work (Bilson et al. 1997), this aspect of textile conservation has not been much investigated. The monitoring of deformation under a constant load is common in engineering, where it is quantified in terms of an engineering metric known as mechanical strain. Applying strain-based techniques to the monitoring of damage caused by hanging tapestries would enable areas of degradation to be identified before it is apparent that damage is occurring, i.e., before it is visible to the naked eye. The research programme seeks to answer the following questions: