Our diverse heritage is not necessarily safe when in museum storage: Acid emissions from wood can lead to the formation of a sodium copper formate acetate (abbreviated ‘socoformacite’) on a variety of objects, such as enamels, containing corroding soda glass in direct contact with copper alloys. This rare corrosion product has hitherto mainly been detected on museum bronzes from sodium rich soils or those which have been treated in sodium solutions. For the first time it is reported here as a mixed glass/metal corrosion product. The exact conditions necessary for its formation need further study. However, it is clear that wood and high relative humidity are unsuitable for the storage of glass and copper objects. Objects which contain wood themselves should be stored in a well-ventilated area or in the presence of absorbents.