Arches Cold Pressed 140lb Watercolor Blocks The world's best known fine art papers, arches is mouldmade from 100% cotton linters. This gives them stability, strength and exceptional tactility. Arches papers are neutral pH which assures their archival quality. Since 1492, every sheet of paper at the Arches mill in Lorraine, France has been carefully manufactured by master craftsmen. Today, Arches assures you of the same superb qualities that have made their papers the most preferred choice of demanding artists for five centuries.