Vergilben

Vergilben is a German verb meaning to yellow or to become yellow, and it is commonly used to describe a color change in organic materials as they age or are exposed to light and heat. The term can be used intransitively (to yellow over time) or transitively (to cause something to yellow). In practice, vergilben often refers to gradual discoloration rather than a sudden change.

Mechanisms of vergilben typically involve chemical aging processes. A primary factor is the oxidation of chromophores, especially lignin in wood and in paper, which produces yellow- and brown-absorbing compounds. Ultraviolet light accelerates photochemical reactions that degrade cellulose and lignin, while heat, humidity, and contaminants or acids can further promote discoloration. The result is a shift toward warmer, yellow-brown tones that may reduce readability or aesthetic value.

Contexts and implications vary. In paper and books, vergilben is a major concern for libraries and archives, signaling aging and potential loss of contrast. In textiles, natural fibers and certain dyes may yellow with sun exposure or laundering. In wood and wood finishes, aging surfaces can develop a yellowish patina or discoloration that affects appearance and durability.

Prevention and remediation focus on slowing the process. Strategies include storing materials away from light, using UV filters, maintaining stable temperature and humidity, and applying deacidification or stabilizers. When discoloration occurs, bleaching or whitening treatments may be used in restoration, but these must be carefully evaluated for material compatibility and long-term effects. Etymology traces to the German components ver- and gelb, with the related noun Vergilbung denoting the process itself.