Abstract: We present a design and test strategy for Geometric Primitive Shadersintegratedcircuits which perform rasterisation of primitives such as vectors and triangles.The design strategy proceeds through various levels of detail, and we describethe need for testing as the design advances. A suitable set of test are given for a typicalshader. Our experiences in applying the strategy to a real device are discussed,together with the tests which we devised, and practical compromises which we had to make.