In this thesis, the author makes several contributions to thestudy of design of graphical materials. The thesis begins with a review of therelationship between design and aesthetics, and the use of mathematical modelsto capture this relationship. Then, a novel method for linking linguistic concepts to colorsusing the Latent Dirichlet Allocation Dual Topic Model is proposed.  Next, the thesis studies the relationship between aesthetics and spatial layout by formalizing the notion of visual balance.  Applying principles of salience and Gaussian mixture models over a body of about 120,000 aesthetically rated professional photographs, the author provides confirmation of Arnhem's theory about spatial layout.  The thesis concludes with a description oftools to support automatically generating personalized design.