Showcases: a really effective mean for protecting artworks? Dario Camuffo a,* , Giovanni Sturaro b , Antonio Valentino b a CNR-ICTIMA, Corso Stati Uniti 4, 35127 Padova, Italy b Consorzio Padova Ricerche, Corso Spagna 12, 35127 Padova, Italy Abstract Field and laboratory tests have been performed to analyse the response of showcases to environmental factors. The following properties have been tested. Thermal damping. Greenhouse effect and IR absorption of the materials most commonly used for panes. Impact of different types of light sources. Humidity buffering capacity and rate. Inside/outside exchanges and leakage. Penetration and deposition of airborne particles. Advantages and disadvantages of airtight and non- airtight showcases in view of protection against dust, corrosive self-outgassing of VOC and microbiological infection and growth. A proposal is made to indicate all of the case characteristics, and their response to the ambient, with appropriate indexes, which represent the level of quality in view of the speci®c problems of the user. A quantitative evaluation of each index quality level is also discussed. # 2000 Elsevier Science B.V. All rights reserved. Keywords: Showcases; Microclimate; Exhibit deterioration; Greenhouse effect; Museum lighting and heating 1. Introduction Showcases are widely used because they are useful to display and protect: in fact they offer a protection against vandalism, robberies and any direct damage that could come from visitors. In addition, often, they are installed for conservation, with the hope that they work as a good `®lter' against environmental attacks due to microclimate variations, chemical pollution and action of micro-organism. Showcases are of key rele- vance in the conservation, and the general principles are reported in two milestone books by Thomson and Stolow [1,2] and, more recently, in [3,4]. The show- case in a museum room is a `box in a box' model, for which another layer of protection works against the `aggressive environment' of modern cities. This model is correct only in the absence of internal perturbing factors, e.g. heating, ventilating and air conditioning systems (HVAC), lighting systems and visitors with their emissions of heat, vapour, organic gases, and transport of external particles. The show- case itself may behave as a greenhouse, emit volatile organic compounds (VOC), or favour the microbio- logical colonisation, or the life of insects. As a con- sequence the quality of the micro-environment inside the case cannot be easily controlled although many efforts are done in this direction. Field and laboratory tests have shown that it is not easy to keep a suitable microclimate inside showcases, for a number of forcing factors, and especially daily temperature and humidity cycles that are in the long run extremely dangerous to exhibits [5]. This paper reports the results of laboratory tests and microclimate observations performed in a number of showcases placed in some museums, i.e. one at the Uf®zi Gallery, Florence; one at the Sainsbury Centre for Visual Arts, Thermochimica Acta 365 (2000) 65±77 * Corresponding author. E-mail address: camuffo@ictr.pd.cnr.it (D. Camuffo). 0040-6031/00/$ ± see front matter # 2000 Elsevier Science B.V. All rights reserved. PII:S0040-6031(00)00614-6