Scoring rule for forming a folding score on a sheet material

A scoring rule for forming a folding score on a sheet material supplied between the scoring rule and an anvil, comprising:

• a pair of score members each individually asymmetrical and comprising an outer scoring surface portion with a flat, planar surface extending at a constant angle from a junction point between the flat, planar surface and an inner scoring surface, the score members coupled to a die board of a die roll of a rotary press, wherein the anvil comprises a flat, compressible rubber-type material joined to an anvil roll of the rotary press, the anvil roll having a flat, curved outer surface bound to the compressible rubber-type material;
• and
• wherein as the sheet material is compressed between the pair of score members and the flat, curved outer surface of the anvil roll, the pair of score members press against a first side of the sheet material, the pair of scoring surface portions form a pair of laterally spaced fold score lines on the first side of the sheet material, the score lines comprising a complementary shape to the scoring surface portions, wherein the score lines each comprise an individually asymmetrical surface, and as the scoring rule engages the sheet material, a second, opposite side of the sheet material is compressed against the flat, curved outer surface of the anvil roll, and the rubber-type material of the anvil bulges towards the die roll and the sheet material and forces the sheet material into an area between the pair of score members forming a self-contained single longitudinally inwardly extending groove on the second, opposite side of the sheet material along a line parallel to and positioned between the laterally spaced score lines.