The present invention relates at least in part to devices which are capable of indicating the presence of moisture. Embodiments of the present invention involve the provision of a solid dispersion of a colour-forming material in a hydrophilic polyurethane material. In particular, although not exclusively, the present invention relates to devices comprising foam, e.g. hydrophilic polyurethane foam and a colour former. Also included in the embodiments of the present invention are methods comprising the use of the devices, and other subject matter.