The automatic synthesis of aesthetically pleasing images is investigated. Genetic programming with multi-objective fi tness evaluation is used to evolve procedural texture formulae. With multi-objective fi tness testing, candidate textures are evaluated according to multiple criteria. Each criteria designates a dimension of a multi-dimensional fi tness space. The main feature test uses Ralph's model of aesthetics. This aesthetic model is based on empirical analyses of fi ne art, in which analyzed art work exhibits bell curve distributions of color gradients. Subjectively speaking, this bell-curve gradient measurement tends to favor images that have harmonious and balanced visual characteristics. Another feature test is color histogram scoring. This test permits some control of the color composition, by matching a candidate texture's color composition with the color histogram of a target image. This target image may be a digital image of another artwork. We found that the use of the bell curve model often resulted in images that were harmonious and easy-on-the-eyes. Without the use of the model, generated images were often too chaotic or boring. Although our approach does not guarantee aesthetically pleasing results, it does increase the likelihood that generated textures are visually interesting.