Billowing silk and bendable binders: is flexibility the key to understanding banner behaviour?

Description/Abstract

Nineteenth century trade union banners designed to be held aloft during outdoor parades and marches needed to withstand the necessary handling and punishment of the wind during use, and rolling for storage. They were frequently constructed from silk fabric and painted on both faces with oil based paints; their manufacture was a quest to impart flexibility to the painted areas of the silk to prolong their useful life span.

On ageing, the most commonly encountered deterioration characteristic of painted banners is splitting and tearing of the silk fabric at the junction between the painted and non-painted regions, due to their differential flexibility. Conservation treatments to support the resultant splits, using adhesive coated fabrics, need to preserve the overall flexibility of the banners to acknowledge the integral characteristics of the artefacts. Moreover, the adhesive support mechanisms need to withstand the continued flexing of the banners during rolling and unrolling, handling and free hanging display.

The paper will discuss how studying the manufacturing methods of two major 19th century banner makers, using analytical techniques to supplement the scant surviving documentary sources, has enhanced understanding of how the flexibility of the banners was initially promoted. Subsequent degradation pathways of the materials and methods used were explored to understand how the original flexibility of banners may have altered. This in turn informed a recent evaluation of past conservation treatments of banners where adhesive techniques had been used. Understanding how the flexible quality of painted banners can influence the behaviour and success of conservation support methods, for example, the quantity and qualities of adhesive needed to endure long term rolled storage, can lead to the development of better remedial conservation techniques.