Most information generated by the general public, particularly for the purpose of decision-support, will inherently contain a spatial component. This spatial data can comprise a very valuable resource for researchers, planners and decision makers, and may be collected for analysis using a Public Participation GIS (PPGIS). The imprecise and abstract nature of the thoughts, feelings and opinions of the public do not, however, lend themselves well to the discrete boundaries enforced by ‘traditional’ GIS data constructs (points, lines and polygons), and as such require data structures that allow for the ‘fuzzy’ nature of these data to be incorporated into their capture, storage and analysis. This paper therefore presents a web-based PPGIS platform with a ‘spray-can’ interface for the capture of fuzzy spatial data; and a relational ‘multi-point-and-attribute’ data structure, which reflects the fuzzy nature of the data, whilst supporting flexible spatial and attribute querying. Whilst the idea of the spray-can interface is not itself novel, the platform demonstrated in this paper has the potential to improve the decision-making process in a number of different areas at a variety of different scales. This is achieved by both increasing levels of interaction with the public through the familiar and user-friendly spray-can interface; and increasing the level of understanding of the spatial and aspatial information that participants contribute, by maximising the potential analytical approaches that may be taken.