23 D. Erhardt and M. Mecklenburg, 'Relative humidity reexamined', ‘Preprints to the IIC Congress’, Ottawa 1994, pp. 32–8.
24 Further tests on lined paintings are planned using optical interferometry, to monitor the strains in the top surface of the painting compared to the strains in the lining resulting from changing the tension. Also, shear tests on lining adhesives with the associated lining material at different RH will give important background information. Additionally, direct measurement of the change in flexural stiffness of the painting using three-point bend tests, compared to the change in tensile stiffness, will help to understand the detailed function of the lining. All information from the above tests can be incorporated into an analytical model to calculate shear strains within the lined painting. Further work is also required to investigate the low RH response in controlled conditions for longer equilibrium times and different initial tensioning conditions. Direct measurement of the moisture transport through the lined painting and the associated thermal gradient requires the development of new sensors that can be incorporated into the composite.