1. Substance: 230g/m2-600 g/m2 2.Grade: B,F200,F300,F400,F500,F600,F700,F800,F1000,FB300,FB500 ... is as following:1. Substance: 230g/m2-600 g/m22.Grade: B,F200,F300,F400,F500,F600,F700,F800,F1000,FB300,FB5003 ... hesitate to send me your inquiry at any time. high grade core board for paper core