Abstract: A fiber optic ribbon includes a plurality of optical fibers arranged in a generally planar configuration having a primary matrix generally contacting optical fibers along a longitudinal axis forming an elongate structure. In one embodiment, the primary matrix has a cross-section with a non-uniform thickness, for example, an end portion with a generally bulbous shape. The fiber optic ribbon is useful as a subunit having a secondary matrix in contact therewith. The secondary matrix has a non-uniform thickness, thereby providing a fiber optic ribbon with preferential tear portions to aid separation of the ribbon into subunits. Other embodiments include a fiber optic ribbon with subunits having a secondary matrix with recessed portions to aid in the separation of the subunits.