A blending model for parametrically defined geometric objects is presented. This blending model, based on a generalized parametric equation, provides insight of the blending nature of many of the curve and surface techniques. It also provides solution to some of the surface/surface intersection and surface/surface blending problems. By carefully designing the blending functions, it can handle 3-sided blending as well. The blending model does not depend on any particular surface representation. CR Categories and Subject Descriptors: 1.3.5 [Computer Graphics]: Computational Geometry and Object Modeling-Geometric Algorithms, Language, and Systems; J.6 [Computer Applications]: Computer-Aided Engineering-computer-aided design (CAD) General Term: Algorithms, Theory Additional Key Words and Phrases: splines, Bezier curves/surface, transition surface, blending surface, surface/surface intersection.