Textures play an important role in the design of synthetic scenes. However, setting textures boundaries independently of the surface mesh edges is still a problem. In this paper, we propose a simple and cheap solution to deal with this problem without modifying the mesh, which introduces an extra cost only for facets containing a texture boundary (by {\em facet}, we mean any kind of surface element (polygon, bicubic patch...), having any kind of parameterisation (barycentric, etc...)). This is achieved by associating to the surface 2D closed curves defining the boundaries of the textures. A pre-processing is done before rendering, clipping and storing these 2D texture trimming curves in each facet, and associating each possible texture to a combination of the areas defined by the curves. At rendering time, the current point is checked relatively to these areas, thus determinating the texture to use on this location of the surface.