SK3

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SK3 is the standard paper stock class . Paper of this material class contains a maximum of 5% woody fibers, but without the use of wood pulp and the weight is approx. 200 grams.

Envelopes or generally thick papers are the best examples of this class of material.

The SK scale goes from SK 1 to SK 15 . Banknotes or securities consist of pure rags , they belong to SK 1 . The higher the SK value, the higher the proportion of wood pulp and thus the opacity of the paper.

Pure newsprint with at least 70% bleached wood pulp is assigned to SK 7 , all types of recycled paper are assigned to SK 12-15 .