Off-Gassing

Off-Gassing

Definition: Off-Gassing refers to the release of volatile organic compounds (VOCs) and other gases from materials as they degrade over time. In the context of framing and art preservation, off-gassing can originate from adhesives, paints, sealants, wood, plastics, or even the artwork itself, posing risks to both the appearance and longevity of framed pieces.

Overview

When materials age, particularly those containing acids, lignin, or unstable synthetic compounds, they can emit gaseous byproducts. These vapors may become trapped inside a sealed frame environment, where they can react with artwork and conservation materials, leading to discoloration, odors, and chemical deterioration. Preventing or mitigating off-gassing is a critical component of archival and conservation framing practices.

Causes

• Wood Products: Natural wood and wood composites (like MDF) emit acids and formaldehyde.
• Adhesives & Tapes: Certain glues and mounting tapes release VOCs as they cure or age.
• Plastics & Acrylics: Lower-grade plastics may release gases during decomposition.
• Artwork Itself: Oil paints, varnishes, and inks can off-gas during drying and aging.

Risks to Artwork

• Causes yellowing or staining of paper and mats.
• Can lead to surface blooming on varnished or coated artworks.
• Promotes chemical deterioration of pigments and substrates.
• May increase acidity inside the framing package, accelerating degradation.

Preventive Measures

• Use archival, lignin-free, and acid-free materials.
• Allow freshly painted or varnished artworks to cure before framing.
• Avoid sealing frames too tightly; allow minimal airflow when appropriate.
• Incorporate molecular traps or other buffering agents inside frames to absorb pollutants.

Best Practices

• Test materials for stability before use in conservation framing.
• Educate clients about the risks of framing freshly created oil paintings or mixed media works.
• Regularly inspect stored or displayed artwork for signs of chemical change.

Related Terms

• Blooming
• Yellowing
• Lignin
• Deterioration