A line of buffered cotton rag mat boards by Bainbridge.
Definition: Alpharag is a premium line of buffered cotton rag mat boards produced by Bainbridge. Considered among the highest standards in conservation and museum framing, Alpharag mats are made of 100% cotton linters, offering superior stability and longevity compared to wood-pulp-derived alternatives.
Bainbridge developed Alpharag as its flagship archival product, surpassing the alpha-cellulose-based Alphamat line. Because Alpharag boards are manufactured from naturally lignin-free cotton, they do not require chemical purification to remove impurities, and they resist acid migration and discoloration over centuries.
Alpharag boards meet or exceed all recognized conservation framing standards, making them suitable for irreplaceable artworks, historic documents, and valuable photographs. The buffering agents (commonly calcium carbonate) help neutralize atmospheric pollutants. Unlike wood-pulp boards, cotton-based mats maintain pH neutrality for the long term without significant degradation.
