Investigating Stitched Support Techniques for Tapestry Using Digital Image Correlation

ABSTRACT This paper reports on an investigation into stitching techniques used to secure woven tapestry artefacts to fabric supports. A research project used digital image correlation (DIC) as a method of evaluating commonly used tapestry support techniques, with stitching tests carried out on wool rep fabric and a historic tapestry fragment. Though it was necessary to first establish parameters for use, DIC proved very helpful for evaluating the effects of these treatments. It demonstrated that damage leads to high levels of deformation and strain, and that extension and creep are mitigated by stitched support. It was shown that a patch support gives good results if the tapestry is damaged in a discrete area, while a full fabric support provides better overall support for weak areas, even if they are not themselves stitched to the support fabric. In general, it was clear that the closer the stitching, the lower the strain. However, comparing global and local strain showed that very closely spaced stitching constrained the stitched area more than the sample overall. This investigation suggests that it is not necessary to carry out intensive stitching to provide good overall support. DIC could allow us to optimise the amount of stitching necessary for a successful support treatment of a tapestry, though further treatment may be carried out to provide visual compensation for loss. It was concluded that both a full stitched support and a partial stitched support in combination with a fabric-covered vertical mount provide effective reinforcement.