Definitions for "Paper grade"
Numerical and terminological description of paper contrast: numbers 0 -1 soft; number 2 normal; number 3 hard; numbers 4 very hard. (see Contrast grade paper & Multigrade)
Is a numerical terminological description of paper contrast: numbers 0-1 soft; numbers 2 normal; number 3 hard; number 4-5 very hard; number 6 ultra hard. Similar grade number from different manufactures do not have the same characteristics.
Papers manufactured to fit within a group or type of papers. Each grade of paper uses basically the same fiber, color, additive and chemical composition.