A fastener comprising: a body having a first surface opposing a parallel second surface, a first face (25a, 27) opposing a parallel second face, the first (25a, 27) and second faces perpendicular to the first and second surfaces (8a, 8b), each of the first and second surfaces (8a, 8b) terminating at a first end and an opposing second end; a channel formed longitudinally into each of the first and second surfaces (8a, 8b), spanning between the first and second ends (35a, 35b), each channel recessed at a depth into a center of the body to form at least one protruding step with an interference edge near the first face (25a, 27) or the second face and extending longitudinally between the first and second ends (35a, 35b), wherein the interference edge of each step terminates at each end (35a, 35b) with a ramp, wherein each of the first (25a, 27) and second faces terminates at each end (35a, 35b) as a tapering sled which meets the end of each ramp of a respective interference edge, wherein the fastener is configured to lock substrates together such that the substrate edges are flush against each other, revealing no portion of the fastener, wherein the second face extends out with at least two spaced apart posts configured as barbed channel locks, wherein each of the at least two spaced apart posts comprise a plurality of barbs being flexible and semi-circle in shape and surrounding an outer surface of each post, wherein the two spaced apart posts are configured to be pressed into barbed post holes of a first substrate with a diameter of the barbed post holes being slightly greater than the diameter of the two spaced apart posts, such that the first face (25a, 27) with the at least one step is exposed for engaging with a corresponding slot (85, 90, 136) formed into a second substrate, wherein radii of the plurality of barbs are wider than a diameter of the barbed post holes, wherein the plurality of barbs flex inward when pressed into the barbed post holes. each channel recessed at a depth into a center of the body to form at least one protruding step with an interference edge near the first face (25a, 27) or the second face and extending longitudinally between the first and second ends (35a, 35b), wherein the interference edge of each step terminates at each end (35a, 35b) with a ramp, wherein each of the first (25a, 27) and second faces terminates at each end (35a, 35b) as a tapering sled which meets the end of each ramp of a respective interference edge, wherein the fastener is configured to lock substrates together such that the substrate edges are flush against each other, revealing no portion of the fastener, wherein the second face extends out with at least two spaced apart posts configured as barbed channel locks, wherein each of the at least two spaced apart posts comprise a plurality of barbs being flexible and semi-circle in shape and surrounding an outer surface of each post, wherein the two spaced apart posts are configured to be pressed into barbed post holes of a first substrate with a diameter of the barbed post holes being slightly greater than the diameter of the two spaced apart posts, such that the first face (25a, 27) with the at least one step is exposed for engaging with a corresponding slot (85, 90, 136) formed into a second substrate, wherein radii of the plurality of barbs are wider than a diameter of the barbed post holes, wherein the plurality of barbs flex inward when pressed into the barbed post holes.