The tensile properties of fibers are determined by the following tests: load-elongation curve, hysteresis, creep, recovery, and relaxation. The results are applicable also to yarns and fabrics. The presence of mechanical tension is of great importance in the degradation of textiles. In the same way the flexibility of the fabric should be preserved, in particular in the restoration process: flexibility of the supporting fabric in case of reinforcement of the original textile and use of adhesives which do not stiffen during aging. See 19-1527. -- AATA