ABSTRACT
The Letter Spirit program is a model of human creativity in the domain of typeface design. The task of Letter Spirit is to take as input a few gridletters, letters rendered on a medium-resolution grid, that are intended to represent the same style. Letter Spirit consists of three modules, each being a relatively complex program solving a vital subtask of gridfont design. The three modules are all based upon an architecture common to the cognitive models implemented by the Fluid Analogies Research Group. The Letter Spirit program has a top-level loop that coordinates the three modules into a single strategy of design called review-and-revision. The design phase of a Letter Spirit run thus amounts to the execution of a loop, in which a letter category is selected and then the Drafter renders a gridletter that, ideally, incorporates the goal style as well as that letter.
