This paper illustrates a diversity of object-oriented languages which differ fundamentally in their support to evolutionary object specification and part-contents manipulation, which are features basic to the modelling of creative design. A case is presented for the modelling of properties as part-objects within a language's object-description scheme.The authors identify a genre of commonly available object-oriented languages as presenting limitations to the flexible description and manipulation of part-objects for the purpose of representing design. Our in-house knowledge-programming language, Splinter, is introduced as contributing a policy for representing concepts with highly structured properties in a way which usefully supports the description of evolving dependency information.The thesis here is that semantically rich description languages may be devised as the domain-independent vehicles from which creative-design modelling architectures can be more directly developed.