No optical brighteners will not yellow with age. It is excellent for watercolor, gouache, pen & ink, acrylics, & calligraphy.

Each block consists of sheets of paper pre-stretched, glued together along all 4 edges, & supported by a rigid backing. The top sheet is easily separated from the block by inserting a knife under the sheet and running it around the edges.

Blocks of 140 lb. paper contain 20 sheets. Blocks of 300 lb. paper contain 10 sheets.