Two desk-top exercises investigated public acceptability of idealized soiling patterns on buildings, using methodologies typical of the psychology of art. The exercises used a range of simulated soiling patterns around a simple architectural element, a pedimented window. In the first experiment respondents were asked to arrange the images from the "most acceptable" pattern to the "least acceptable". Results hinted at the importance of certain soiling features in driving the ranking. The second exercise explored the characteristics of soiling patterns that most affected their acceptability. In this experiment the images were organized in pairs. People were requested to choose the pattern they found more acceptable in each pair. Uniform patterns and those which created shadowing effects proved more acceptable. Patterns with non-integer fractal dimension that obscured architectural forms were less acceptable. There was usually a preference for images showing less soiling, whereas vertical features and lumpiness were not as acceptable. Results gave an insight into spatial factors that might influence the acceptability of soiling on real buildings. Thus suggesting it is necessary to consider both the level and the distribution of soiling when trying to gauge public reaction.