When choosing a FRAME BACKING you can choose either a pH-neutral board or an acid-free board. If you are planning on keeping your framed image as a long-term display piece, an acid-free backing is the better choice.
We stock three different materials for frame backings:
• Corrugated Cardboard - White, 1/16" E-flute for sizes 12 x 16" and smaller; 1/8" thick B-flute for larger sizes.
• Matboard - White, pH-neutral, buffered, 1/16" thick.
• Foam Board - White, acid-free, buffered, 1/8" thick. Approved by the Library of Congress for indefinite-term storage (hundreds of years).