Leeching

Leeching

Definition: Leeching refers to the process by which acidic or chemically active substances migrate from materials such as backing boards, mats, or adhesives into the artwork, leading to discoloration, staining, or long-term degradation. This phenomenon is particularly relevant in paper-based artwork, photographs, and archival materials, where contact with non-archival or acidic components can cause visible damage over time.

Causes of Leeching

• Acidic Backing or Matting: Materials like non-archival cardboard, some foam boards, or inexpensive mats can release acids that migrate into the artwork.
• Improper Adhesives: Adhesives that are not pH-neutral or conservation-grade may leach chemicals into the art surface.
• Environmental Conditions: High humidity and fluctuating temperatures can accelerate the migration of acids and other harmful compounds.

Effects on Artwork

• Discoloration of paper, often appearing as yellowing or brown spots.
• Staining along the edges of mats or backing materials.
• Long-term weakening or brittleness of paper fibers.
• Compromised archival integrity of valuable prints, photographs, or historical documents.

Prevention and Conservation

• Use acid-free or buffered mat boards and backing materials.
• Employ conservation-grade adhesives and hinging methods (e.g., Hinging Tape or Japanese paper hinges).
• Maintain stable environmental conditions with controlled humidity and temperature.
• Regular inspection of framed artwork to detect early signs of leeching or acid migration.
• Consider conservation matting for valuable or irreplaceable works.

Related Terms

• Acid Migration
• Acid Burn
• Ph
• Yellowing