This is 100 GSM paper, which is the perfect thickness for bookbinding, especially for the book cover sheets and end sheets. Normal paper and wrapping paper on the market is around 80 GSM, which you will find out is difficult to apply onto the bookbinding boards when the paper is thin, it is easy to wrinkle, warp and create problems while gluing. At the same time, it will be better to use thicker paper as end sheets, as we have done many restorations, the book with thicker end sheets always last longer than thin end sheets.