Yasutomo Mineral Paper is crafted from calcium carbonate gathered from rocks instead of tree pulp like traditional wood based paper. This makes Mineral Paper an environmentally friendly alternative. Composed of 80% calcium carbonate and bonded together with a small amount of HDPE (plastic); Mineral Paper has very unique qualities such as tear and water resistance and it will not bleed through even when soaked. Mineral Paper?s absorbency is great for almost any media, wet or dry, and can be used in ink jet printers (results will vary based on printer). The bright white color and vellum surface of the paper allows for crisp lines, and saturated colors.100 lb./150gsm. Acid-free.