Acid-free foam core is a specialized mounting board designed for preservation framing. It consists of an inert, lightweight foam center sandwiched between two layers of acid-free paper. This construction provides rigidity and support while ensuring that the board will not release harmful acids that could damage artwork, photographs, or documents over time.

Key Features

Acid-free surface: Both sides are laminated with acid-free paper, preventing acid migration into the artwork.
Lightweight: Easier to handle and mount compared to denser backing boards.
Inert foam core: The interior foam is chemically stable and non-reactive.
Versatility: Commonly used for mounting photographs, prints, textiles, and lightweight artworks.

Uses in Framing

Mounting artwork: Provides a supportive, stable base for attaching artwork through hinges or dry mounting techniques.
Backboards: Used as a protective backing layer within a frame package to add strength without excess weight.
Exhibition displays: Ideal for temporary or traveling exhibitions, since it is lightweight yet rigid.

Advantages

Archival safety: Prevents staining, discoloration, or deterioration caused by acidic materials.
Easy cutting: Can be trimmed cleanly with mat cutters or utility knives for custom sizes.
Dimensionally stable: Resists warping better than some paper-based boards.

Comparison to Other Substrates

Unlike standard foam core, which may contain acidic paper liners, acid-free foam core is engineered specifically for long-term preservation. It offers a safer alternative to traditional mounting boards such as adhesive coated boards or plastics like Sintra and Dibond, which are better suited for signage or commercial display. Acid-free foam core strikes a balance between archival safety and ease of use, making it a favorite in conservation and fine art framing.

Framing Industry Context

The introduction of acid-free foam core transformed mounting practices in the framing industry. Before its availability, framers often used cardboard or regular foam core, which released harmful acids over time. Today, acid-free foam core is considered a standard material for conservation framing, ensuring that framed works remain protected for decades without risk of chemical degradation.

Acid-Free Foam Core