Nikka pellet, which is montmorillonite clay specially treated with water glass and sulphuric acid, is utilized as a humidity buffering agent for shipping and exhibition of works of art in Japan. Although it has excellent humidity buffering capacity at the equilibrium point, it has a rather poor response to rapid changes in temperature. Japanese tissue paper has a good response to rapid change in temperature, and the combination of Nikka pellet and Japanese tissue paper with the aid of a hydrophilic binder makes an excellent humidity buffer with a rapid response to changes in temperature.