Buffered Mat refers to a type of mat board that has been treated with calcium carbonate during manufacturing to adjust and stabilize its pH level. This buffering process helps neutralize acids that may be present in the mat or in adjacent materials, providing additional protection for artwork, photographs, and documents over time. Buffered mats are commonly used for preservation framing where archival stability is important.

Construction and Material

Core Material: Usually made from high-quality paper, alpha-cellulose, or cotton rag.
Buffering Agent: Calcium carbonate is added to the mat core to neutralize acids and maintain a slightly alkaline pH (typically around 7.5-8.5).
Facing Layer: The visible top layer may be colored, textured, or smooth, similar to standard mat boards.
Acid-Free Base: Buffered mats are typically also acid-free to prevent acid migration from the mat to the artwork.

Purpose and Benefits

Acid Neutralization: Helps counteract acids from the mat, mounting adhesives, or environmental sources.
Long-Term Preservation: Ideal for archival framing and for protecting valuable prints, photographs, and documents.
Compatibility: Suitable for paper-based artwork and many types of printed media.
Cost-Effective: Provides preservation benefits without requiring specialized museum board for every project.

Use Cases

Framing certificates, diplomas, and archival documents.
Protecting photographic prints and art prints intended for long-term display.
When conservation framing is desired but museum-grade board is not required.
Projects where environmental acid exposure is a concern.

Comparison with Other Mats

Rag Mat / Cotton Rag: Made from 100% cotton fiber; naturally pH neutral, often preferred for high-value archival work.
Cotton Linters: Mats made from short cotton fibers; often acid-free but may not be buffered unless specified.
Acid-Free Mat: Prevents introduction of acids from the mat itself but may not provide additional buffering against environmental acids.

Best Practices

Verify that the buffered mat is compatible with the artwork, especially for sensitive papers or prints.
Consider pairing buffered mats with UV-filtering glazing to maximize preservation.
Always handle mats with clean hands or gloves to avoid contamination.
Check manufacturer specifications for pH level and buffering stability if archival quality is critical.

Buffered Mat