A split mold insert for defining a relief portion of a molded article, comprising: a body defining a mold cavity for the relief portion of the molded article , the body having a male projecting portion with a shutoff face , the shutoff face for selectively defining, in a molding configuration of the split mold insert, a parting line with an adjacent mold stack component and, in a cleaning configuration of the split mold insert, a molding surface, the male projecting portion having an outer surface configured to cooperate with a female receptacle associated with the adjacent mold stack component to provide a melt barrier in the cleaning configuration of the split mold insert, the body being split into a plurality of split mold insert parts that are separable for ejection of the molded article, each split mold insert part having a mating face for mating with a complementary mating face of an adjacent one of the split mold insert parts, the mating face having an inner face region adjacent to the mold cavity, an offset , and an outer face region on an opposite side of the offset from the inner face region, wherein the offset of each split mold insert part has a first portion that is substantially parallel to an axis (A) of the split mold insert part; characterized in that the offset of each split mold insert part has a second portion that diverges from the axis towards the outer surface of the male projecting portion and terminates at the outer surface, wherein at least a part of the inner face region of each split mold insert part terminates at the shutoff face of the male projecting portion, and wherein the offset of each split mold insert part is configured to cooperate with the offset of the adjacent one of the split mold insert parts to prevent melt from passing between the offsets and to guide melt towards the melt barrier. a body defining a mold cavity for the relief portion of the molded article , the body having a male projecting portion with a shutoff face , the shutoff face for selectively defining, in a molding configuration of the split mold insert, a parting line with an adjacent mold stack component and, in a cleaning configuration of the split mold insert, a molding surface, the male projecting portion having an outer surface configured to cooperate with a female receptacle associated with the adjacent mold stack component to provide a melt barrier in the cleaning configuration of the split mold insert, the body being split into a plurality of split mold insert parts that are separable for ejection of the molded article, each split mold insert part having a mating face for mating with a complementary mating face of an adjacent one of the split mold insert parts, the mating face having an inner face region adjacent to the mold cavity, an offset , and an outer face region on an opposite side of the offset from the inner face region, wherein the offset of each split mold insert part has a first portion that is substantially parallel to an axis (A) of the split mold insert part; characterized in that the offset of each split mold insert part has a second portion that diverges from the axis towards the outer surface of the male projecting portion and terminates at the outer surface, wherein at least a part of the inner face region of each split mold insert part terminates at the shutoff face of the male projecting portion, and wherein the offset of each split mold insert part is configured to cooperate with the offset of the adjacent one of the split mold insert parts to prevent melt from passing between the offsets and to guide melt towards the melt barrier. <EOS>