A very durable 55-lb. white paper, with a slight latex content, which makes it great for marbling since it is not harmed or weakened when it gets wet, it won't rip or tear easily, and doesn't shrink or wrinkle when it dries. Great for bookbinding. It feels almost like a smooth linen.
This is an industrial printing paper, which you won't ever find in art supply stores. I use this paper when I want a truly professional, archival quality and look. Grain goes long way. There is a minimum order of 10 sheets.