A reticle for use in a photolithography process for exposing a photoresist layer in the production of a component which is formed from a plurality of adjacent exposed areas, comprises: an exposure aperture adapted to allow light to pass through the reticle; a patterned area within said exposure aperture which defines at least part of the functional design of the component; and one or more "stitching" structures located close to one or more of the edges of the exposure aperture, said "stitching" structures being arranged to create "stitching" marks on the photoresist, which can be used to determine whether said adjacent exposed areas have been accurately positioned.