A downhole tool to be rotated for cutting rock to form a borehole comprising: a body with a center axis about which the downhole tool rotates; a plurality of blades (402, 403) comprising elongated raised areas on the body arrayed around the center axis, the plurality of blades (402, 403) defining a plurality of channels between the plurality of blades (402, 403), each of the plurality of blades (402, 403) having a front wall partially defining one of the plurality of channels and a leading edge of the blade, and a back wall partially defining another one of the plurality of channels; wherein each of the plurality of blades (402, 403) has arranged along of the leading edge of the blade a plurality of cutters in fixed positions on the blade; and wherein at least one of the plurality of blades (402, 403) is an offset blade, the offset blade comprising at least two portions, the at least two portions comprising a first blade portion and a second blade portion; the leading edge of the offset blade comprising a first leading edge portion and a second leading edge portion corresponding to the first and second blade portions, the second leading edge portion of the leading edge of the offset blade being angularly offset from the first leading edge portion to form a step in the leading edge of the offset blade and the front wall without forming an opening in the offset blade extending between the front wall and rear wall of the offset blade; characterized in that: the offset blade comprises a top surface from which the plurality of cutters extend; the back wall has a top edge that, along at least a portion of the back wall, is lower than the top surface; and the offset blade comprises a sloped back surface extending from the top surface to the lower portion of the top edge of the back wall, the sloped back surface narrowing a width of a top of the offset blade without narrowing a base of the offset blade. a body with a center axis about which the downhole tool rotates; a plurality of blades (402, 403) comprising elongated raised areas on the body arrayed around the center axis, the plurality of blades (402, 403) defining a plurality of channels between the plurality of blades (402, 403), each of the plurality of blades (402, 403) having a front wall partially defining one of the plurality of channels and a leading edge of the blade, and a back wall partially defining another one of the plurality of channels; wherein each of the plurality of blades (402, 403) has arranged along of the leading edge of the blade a plurality of cutters in fixed positions on the blade; and wherein at least one of the plurality of blades (402, 403) is an offset blade, the offset blade comprising at least two portions, the at least two portions comprising a first blade portion and a second blade portion; the leading edge of the offset blade comprising a first leading edge portion and a second leading edge portion corresponding to the first and second blade portions, the second leading edge portion of the leading edge of the offset blade being angularly offset from the first leading edge portion to form a step in the leading edge of the offset blade and the front wall without forming an opening in the offset blade extending between the front wall and rear wall of the offset blade; characterized in that: the offset blade comprises a top surface from which the plurality of cutters extend; the back wall has a top edge that, along at least a portion of the back wall, is lower than the top surface; and the offset blade comprises a sloped back surface extending from the top surface to the lower portion of the top edge of the back wall, the sloped back surface narrowing a width of a top of the offset blade without narrowing a base of the offset blade. the offset blade comprises a top surface from which the plurality of cutters extend; the back wall has a top edge that, along at least a portion of the back wall, is lower than the top surface; and the offset blade comprises a sloped back surface extending from the top surface to the lower portion of the top edge of the back wall, the sloped back surface narrowing a width of a top of the offset blade without narrowing a base of the offset blade.