Acrylic casework rarely wears out. What it does instead is get cleaned to death: a few years of dry paper towels and whatever spray bottle the evening crew carries, and a case that left the shop at Museum Archival Finish reads hazed and scuffed under gallery lighting. The material is not fragile — it is specific. It has a short list of things it cannot tolerate, all of them common in janitorial closets, and a very simple routine that keeps it clear indefinitely. This is that routine, written to be handed to the people who actually do the cleaning.
The one rule that prevents most damage: never dry-wipe
Gallery dust is not soft. It is grit — and a dry cloth dragged across acrylic turns that grit into an abrasive, scribing thousands of micro-scratches that individually are invisible and collectively read as haze. Dry-dusting is how most acrylic casework degrades, one well-intentioned wipe at a time, and it is the habit this protocol exists to replace.
The correct baseline: a clean, soft microfiber cloth and liquid — either a cleaner sold specifically as acrylic-safe (plastic polishes and anti-static acrylic cleaners) or a mild solution of dish soap in water. Wet the surface or the cloth, let the liquid float the dust, wipe gently, and finish with a dry area of the microfiber only once the grit is off the surface. Blot rather than grind. That is genuinely the whole technique; everything else in this post is about what to keep away from the case.
Know the killers by chemistry class
Acrylic’s weakness is not water, and not soap — it is solvents and aggressive cleaning chemistry, which attack the material itself rather than the dirt. Published acrylic sheet-manufacturer care guidance is consistent on all three classes:
- Ammonia-based glass cleaners. The blue bottle is the classic acrylic killer, precisely because a clear case looks like glass to whoever is cleaning it — and ammonia cleaners attack acrylic and cloud it over repeated use.
- Solvent wipes and strong solvents — acetone, lacquer thinner, aromatic solvents. These soften and craze the surface on contact.
- Alcohol-heavy products, including many sanitizing wipes and sprays. Alcohol exposure is a known crazing driver on acrylic — a hazard that got much more common when sanitizing everything became reflex.
Crazing, in one sentence: a network of fine surface micro-fractures that appears when acrylic under stress meets an aggressive chemical, and it is permanent — you cannot polish out cracks that go into the surface. Bonded casework is most vulnerable near its joints, where fabrication stress concentrates, which is why a sanitizing wipe run along a vitrine’s bonded corner is close to the worst single act of maintenance possible. The warning to write into the SOP: if the product isn’t acrylic-safe or mild soap, it doesn’t touch the case — and that includes “just this once” during flu season.
Static: why the case you just cleaned is already dusty
Acrylic charges electrostatically when rubbed — so a vigorously wiped case becomes a dust magnet, pulling airborne particles back onto the surface within hours. Two practical answers: use an anti-static acrylic cleaner as the routine product (they neutralize the charge that ordinary wiping builds), and wipe gently rather than buffing hard, since the charging scales with the rubbing. In practice this meaningfully stretches the interval between cleanings — the case stays clear longer because it stops pulling dust toward itself.
Scratch triage, honestly
When a case does pick up damage, the escalation ladder runs:
- Light scuffs and fine scratches — often reducible with a dedicated acrylic polish and a soft cloth, worked gently over the local area.
- Deeper scratches that catch a fingernail — a progressive abrasive-then-polish repair. This is real refinishing work: done properly it restores clarity, done casually it leaves a lens-like distortion where the surface was locally re-profiled. On display surfaces judged at close range, that distortion can be more visible than the scratch was — worth knowing before anyone attacks a sight surface with a kit.
- Panel replacement — when damage is deep, widespread, or sits front-and-center on a sight surface. On a bonded case this is a fabrication decision (a bonded panel is not a screw-off part), and at some point refinishing a heavily worn case costs more in result than replacing the cover — a judgment call we would rather make with you than after a refinishing attempt.
Triage judgments should use the case’s own spec: a surface built to Display Finish is judged at approximately 2 feet; Museum Archival at approximately 1 foot. A mark invisible at the case’s inspection distance is a maintenance note, not an emergency.
The one-page SOP
Condensed for the wall of the prep room:
- Routine (weekly or as scheduled): microfiber + acrylic-safe anti-static cleaner or mild soap solution. Wet first, wipe gently, blot dry. Never dry-wipe.
- Never on the case: ammonia glass cleaners, solvent or sanitizing wipes, alcohol sprays, paper towels, dry dusters.
- Corners and joints: gentlest treatment, no aggressive products ever — this is where crazing starts.
- Damage: photograph it, note whether it is visible at the case’s inspection distance, and escalate rather than improvising a repair on a sight surface.
- Supplies cart: keep the acrylic-safe products on the gallery cart. The protocol that requires a trip to a different closet is the protocol that gets skipped.
A case maintained this way holds the finish grade it was fabricated to for decades — the material is that stable when the chemistry stays friendly. And when a case in your galleries is already past what maintenance can recover, that is a fabrication conversation: send photos and dimensions and we can talk panel replacement versus a new cover against the casework standards it was (or should have been) built to.
