Supported catalyst particles and single crystals exhibit differences in catalytic properties which are referred to as the structure gap in catalysis. Experimentally this is addressed by systematic studies of the influence of e.g. particle size and structure, and type of support on the catalytic properties. Modern microfabrication adds new opportunities, complementing the existing ones, to systematically manufacture and evaluate supported model catalysts. In this presentation the advantages and limitations of different microfabrication techniques are briefly reviewed. The use of electron beam lithography (EBL) applied to model catalyst production is described in detail. Specific examples are given of EBL manufactured noble metal catalysts on different supports. Evaluation of these catalysts in catalytic reactions involve (i) studies of morphological changes of the native structures caused by the reaction conditions and (ii) evaluation of the kinetics.