Abstract: To model surface imperfections and weathering, we propose a two-step texture generation framework in between manual texture synthesis and automatic physical simulation. Although the pattern of blemishes looks random, the systematic and geometry dependent nature of the underlying distribution is still observable. A distribution of tendency (potential to contain blemishes) is modeled in the first step, which includes user control and geometric information. The second generates and distributes an irregular blemish pattern according to the modeled tendency distribution. As examples we model three common surface imperfections; dust accumulation, patina and peeling.