A Library Spectrogram describes a library collection by visualising the relative quantity of materials under each of its Dewey subject headings. Each Dewey class is represented by a different colour. Different shades of each colour represent the divisions within each class. The Library Spectrogram is now integrated as an interactive tool for browsing within UTS Library’s catalogue search. The spectrum makes understanding, browsing and comparing library collections more intuitive and engaging. The concept was initially rendered as an educational wall chart as part of the Shelf Life exhibition.