E. Gerber Full Backs Silver/Gold (50 Count Pack)

24 mil, acid-free, 3% buffered backing board.
Genuine acid-free, cellular fiber.
Meets strict U.S. Government standards for archival storage.
3% calcium carbonate buffer throughout, maintains a neutral pH.
White on both sides.
The highest quality backing board available anywhere.
7 1/2" x 10 1/2"