An adaptable technique for micropatterning biomaterial scaffolds has enormous implications in controlling cell function and in the development of tissue-engineered (TE) microvasculature. In this paper, we report a technique to embed microscale patterns onto a collagen-glycosaminoglycan (CG) membrane as a first step toward the creation of TE constructs with built-in microvasculature. The CG membranes were fabricated by homogenizing a solution of type-I bovine collagen and chondroitin-6-sulfate in acetic acid and vacuum filtering the solution subsequently. The micropatterning technique consisted of three steps: surface dissolution of base matrix using acetic acid solution, feature resolution by application of uniform pressure, and feature stability by glutaraldehyde cross-linking. Application of the new technique yielded patterns in CG membranes with a spatial resolution on the order of . We show that such a patterned matrix is conducive to the attachment of bovine aortic endothelial cells. The patterned membranes can be used for the development of complex three-dimensional TE products with built-in flow channels, as templates for topographically directed cell growth or as a model system to study various microvascular disorders where feature scales are important. The new technique is versatile; topographical patterns can be custom made for any predetermined design with high spatial resolution, and the technique itself can be adapted for use with other scaffold materials.