Levels of temperature and relative humidity promised by organizers of exhibitions may not relate closely to the environment that is actually provided for borrowed objects. Environmental parameters specified by lenders to exhibitions can be very restrictive but may not relate closely to the recent environmental history of the object, or to the sensitivity of the object to changes in temperature or relative humidity. Theoretical knowledge of the relationship between the environment and dimensional change in organic objects has not been matched by an understanding of how real objects react in actual display conditions. A little more understanding and honesty might lead to a less restrictive attitude without increasing the risk to loaned objects. An appendix describes an experiment which measured the sensitivity of a wood panel to environmental fluctuations in an exhibition space. The results suggest that specifications for variance of relative humidity could be relaxed.