Art faces many threats while in storage, on view, or in transit. Light exposure, physical impact, theft, and environmental factors pose risks to art’s integrity. Yet, experts agree that no factor acts as destructively and pervasively as humidity. Unlike a crack in a canvas or a scratch on a frame, moisture-related damage develops invisibly and is mostly irreversible. Read on to understand how humidity ruins artwork and develop a humidity-proof storage and shipping strategy.

How Humidity Ruins Artwork

The relative humidity convenient for artwork is within the range of 45-55%. Anything below or above this range is hazardous for delicate organic materials, of which artwork is made. Wood, panels, canvas, paper, and organic paint pigments are susceptible to humidity fluctuations and can develop internal stresses as a result of drying and dampening cycles.

Let’s see how humidity affects specific types of art.

• Canvas paintings and panels. Oil and tempera paintings are the most humidity-sensitive art objects. Canvas reacts to moisture by expanding, which causes its slackness; drying out afterward makes the canvas contract and pull taut. Panel paintings warp and delaminate under the influence of moisture. Additional hazards like mold and mildew develop when humidity levels are higher than normal for a long time.
• Works on paper and photos. Paper is also sensitive to moisture; high humidity accelerates acid degradation and causes paper to yellow and become brittle. This process is termed hydrolysis in professional circles. Paper gets cockled, warped, and adhesive. Historic photographs are at the highest risk, with gelatin silver prints suffering emulsion lifting, and albumen prints cracking even under slight humidity deviations.
• Textiles. Textiles weaken and rot when stored in damp conditions, while metal threads in the fibers are exposed to rapid oxidation.

In each of these cases, fluctuating humidity is the leading cause of structural deterioration of art. Stability matters more than an ideal humidity level, even if you can’t strike the gold standard of the 45-55% range.

Heightened Humidity Risks in Transit

Artwork is the most vulnerable to humidity during long-distance and international transportation. Shipping environments often have different humidity and temperature conditions, and the artwork’s handover exposes it to dangerous fluctuations. Knowing how humidity ruins artwork equips you with insightful tips for packing art with climate-buffering materials, such as silica gel, moisture-barrier lining, and proper cushioning. Sealing humidity trackers inside boxes or crates also gives you data on internal humidity, preventing damage during the periods when your art is outside your control.