The owner wife asks why the watercolour that has hung in the sunlit skylounge for three seasons looks washed out. It is not washed out. It has faded, the fading is photochemical, and nobody on earth can put the colour back. She asks whether the stews have been cleaning it. They have not. The window did it.
Light and Ultraviolet
Light damage is cumulative and irreversible. Every hour of exposure spends a little more of a work that cannot be topped up. UV is the worst of it, but visible light fades too, and there is no completely safe dose for a fugitive medium.
- Most at risk: watercolour, gouache, inks, dyed textiles, photographs, colour prints, works on paper.
- Controls: UV-filtering glazing and window film, blinds and shades closed when a space is empty, never hang a work opposite a picture window, aim spotlights so the beam falls off the work, prefer low-output LED to halogen.
Heat
Chemical ageing roughly doubles for every 10 C rise. Heat softens adhesives, waxes and resins, blooms varnish, opens veneer and marquetry, and can slump contemporary media outright. Never hang art on a bulkhead with a hot space behind it, and never directly above a heat source or under a tight spot.
Humidity and Salt
Wood, canvas, paper, ivory and vellum are hygroscopic: they take up and give off moisture and physically move as they do. Swings in relative humidity are far more damaging than a steady imperfect level. Salt aerosol is both corrosive and hygroscopic, so it keeps drawing moisture to the surface it has settled on.
| Material | Agent of deterioration | Control |
|---|---|---|
| Oil on canvas | RH swings, vibration | Stable RH, no vent or porthole nearby, secure fixings |
| Works on paper | UV and visible light | UV glazing, blinds closed, low lux, rotate off display |
| Antique furniture | Heat and dry air | Keep clear of heat sources; steady RH |
| Bronze, silver | Salt aerosol, humidity | Doors and ports shut; stable dry air; no polishing |
| Textiles, tapestry | Light and pests | Low light; housekeeping; report any insect activity |
Physical Forces
Vibration from engines, generators and thrusters fatigues paint films, loosens joints and slowly walks a sculpture towards the edge of its plinth. Motion in a seaway turns an unsecured object into a projectile. Shock from a slamming door or a dropped case travels straight through the structure into the frame.
Pests, Pollutants and People
Moth and beetle arrive in flowers, provisions and soft furnishings. Cooking grease, exhaust soot and cleaning-product vapour deposit on surfaces you cannot then clean. And people, always people: a guest resting a glass on a plinth is a real, routine, expensive risk.
Onboard Notes
- Fading, chemical ageing and mould are permanent. Prevention is the whole job.
- Steady is better than perfect: hold the environment rather than chase a number.
- If you see mould, insects or a change in a surface, photograph it and report it. Do not treat it.