A refiner plate segment (205, 305,...) for a mechanical refiner, the refiner plate segment (205, 305,...) comprising a substrate (205, 309,...) having: a radial length; a narrow side (211,...) disposed at a first end (203,...) of the radial length; a wide side (213,...) disposed at a second end (207,...) of the radial length, the wide side (213,...) located radially distant from the narrow side (211,...) along the radial length, the wide side (213,...) being wider than the narrow side (211,...); a first lateral side (217,...) extending between the narrow side (211,...) and the wide side (213,...) along the radial length; a second lateral side (218,...) extending between the narrow side (211,...) and the wide side (213,...) along the radial length, the second lateral side (218,...) being distally disposed from the first lateral side (217,...); and a back face (212,...) oppositely disposed from a front face (219,...) along a thickness, the back face (212,...) and the front face (219,...) extending between the wide side (213,...), narrow side (211,...), first lateral side (217,...), and second lateral side (218,...), wherein the front face (219,...) further comprises an area having a plurality of alternating breaker bars (225, 325,...) and wide grooves (227, 327), wherein the breaker bars (225, 325,...) engage the substrate (209,...) and wherein adjacent breaker bars (225, 325,...) and the substrate (209,...) define a wide groove (227, 327) between the adjacent breaker bars (225, 325,...), wherein the substrate (209,...) further comprises a variable substrate profile (210,...) disposed between the wide side (213,...) and the narrow side (211,...), the variable substrate profile (210,...) comprising: a trough (235, 335,...) at a first radial position on the front face (219,...), an adjacent crest (239, 339,...) at a second radial position on the front face (219,...), wherein the front face (219,...) connects the trough (235, 335,...) and the adjacent crest (239, 339,...), and wherein the substrate (209,...) further comprises a water channel (250, 350,...) having a first end (251, 351,...) disposed closer to the narrow side (211,...) than a second end (252, 352,...). a radial length; a narrow side (211,...) disposed at a first end (203,...) of the radial length; a wide side (213,...) disposed at a second end (207,...) of the radial length, the wide side (213,...) located radially distant from the narrow side (211,...) along the radial length, the wide side (213,...) being wider than the narrow side (211,...); a first lateral side (217,...) extending between the narrow side (211,...) and the wide side (213,...) along the radial length; a second lateral side (218,...) extending between the narrow side (211,...) and the wide side (213,...) along the radial length, the second lateral side (218,...) being distally disposed from the first lateral side (217,...); and a back face (212,...) oppositely disposed from a front face (219,...) along a thickness, the back face (212,...) and the front face (219,...) extending between the wide side (213,...), narrow side (211,...), first lateral side (217,...), and second lateral side (218,...), wherein the front face (219,...) further comprises an area having a plurality of alternating breaker bars (225, 325,...) and wide grooves (227, 327), wherein the breaker bars (225, 325,...) engage the substrate (209,...) and wherein adjacent breaker bars (225, 325,...) and the substrate (209,...) define a wide groove (227, 327) between the adjacent breaker bars (225, 325,...), wherein the substrate (209,...) further comprises a variable substrate profile (210,...) disposed between the wide side (213,...) and the narrow side (211,...), the variable substrate profile (210,...) comprising: a trough (235, 335,...) at a first radial position on the front face (219,...), an adjacent crest (239, 339,...) at a second radial position on the front face (219,...), wherein the front face (219,...) connects the trough (235, 335,...) and the adjacent crest (239, 339,...), and a trough (235, 335,...) at a first radial position on the front face (219,...), an adjacent crest (239, 339,...) at a second radial position on the front face (219,...), wherein the front face (219,...) connects the trough (235, 335,...) and the adjacent crest (239, 339,...), and wherein the substrate (209,...) further comprises a water channel (250, 350,...) having a first end (251, 351,...) disposed closer to the narrow side (211,...) than a second end (252, 352,...).