What score rule heights should I use for the different styles of Shreiner Matrix?
Every day we run into companies that are dead set on .937 knife and .918 crease for all of their dies. I am a firm believer in “if it’s not broken, don’t fix it”, but this is not what we recommend for crease rule in one’s die. The general formula we use to determine crease rule height is (knife height - board thickness = crease rule height). This is the formula for any mylar backed or one piece extruded matrix. When dealing with metal base matrix one must remember to subtract an additional .005” to .007” to account shim height in the matrix. One important thing to remember is, this is only a general rule. Some instances require a diversion from the norm in order to get a good crease, for example, a die that has multiple creases and/or double creases may require a lower scoring rule.
The width of the scoring rule mainly depends on the thickness of the substrate. For most lighter stocks, .008” - .020”, 2 point rule is sufficient. Once you move to a heavier stock, .020” +, it may be more beneficial to move to a 3 or 4 point rule, depending on the situation. We also recommend that when creasing thicker substrates one should compress the material a couple of thousandths. One will actually be able to see the imprint of the score rule in the material. By compressing the material you actually force the crease to form and the board to delaminate, which in turn gives you a better score.
cutting rule height “c” - board thickness “b”) - .009 “d” = crease rule height “a”
Shreiner Profile and Shreiner Fiberboard
cutting rule height “c” - board thickness “b” = crease rule height “a”