Abstract: In this paper we propose to tessellate a region by growing curves. We use a particle system, which flexibly provides good control over the final effects by variations of the initial placement, the placement order, curve direction, and curve properties. We also propose an automatic image-based mosaic method which has good texture indication, using a smoothed vector field to guide particle movement. The final irregular tessellation simulates stained glass where the elongated curved tiles suggest the content of highly textured areas. We give some additional applications, some of which resemble naturally occurring irregular patterns such as cracks and scales. We also notice that stacking a set of curves in a structured way can produce the illusion of a 3D shape.