Exhibit design conversations about display cases usually start with sightlines and clarity. Conservation conversations start somewhere else entirely: the case is part of the object’s environment. Once a vitrine closes over an artifact, everything inside that enclosed volume — the glazing, the adhesives that bonded it, the gaskets, the deck materials, the fabrics and paints on the base — shares an atmosphere with the object for years. Materials that are perfectly inert to a person handling them can release compounds over time that corrode metals, fox paper, or degrade organic materials. That is the premise a conservator brings to the first call, and a fabricator who wants to build for institutions has to start from the same place, not from aesthetics.
This post lays out how that premise shapes the construction of a bonded acrylic case: where off-gassing actually comes from in fabrication, the sealed-versus-ventilated decision that drives the design, and the working protocol between a fabrication shop and a collections department.
Where off-gassing comes from in a bonded acrylic case
An honest inventory, because the conversation goes better when the fabricator volunteers it:
- Adhesive residues. Solvent cements and two-part adhesives are the structural heart of a bonded case, and both continue releasing volatiles after the joint looks finished. Cure is a process, not a moment — which is why schedule matters below.
- Everything that isn’t acrylic. Gasket materials, sealants, deck coverings, paints and coatings on bases, and any wood or composite in the case’s plinth or interior architecture. In conservation practice these are frequently the materials of greatest concern — more so than the glazing itself.
- Accumulated interior surface area. A case design with long bonded seams, large adhesive fillets, or generous interior trim carries more emitting surface inside the sealed volume than a design that does the same structural job with less. Construction choices change the denominator.
Two consequences follow directly. First, schedule the cure: a case destined for a collection should be bonded, then given its full cure and airing time before any object goes inside — and that time belongs in the production plan from the start, not discovered at installation. The institution’s own guidelines govern how long; the fabricator’s job is to make the calendar accommodate them. Second, design for less adhesive exposure: joint layouts that achieve the structure with cleaner, smaller bond lines are better conservation design as well as better-looking fabrication.
Sealed or ventilated: the decision that drives the construction
The central fork in conservation case design is whether the case is a sealed microclimate or a passively ventilated enclosure, and it is the conservator’s call — driven by the object’s sensitivity, the gallery’s environment, and the institution’s monitoring practice. Each answer demands different things from the fabrication:
Sealed microclimate cases are built to hold a conditioned interior environment, often with silica gel or other conditioning media maintaining humidity. For the fabricator that means joint continuity treated as an environmental boundary rather than only a structural one, gasketed access designed to compress consistently, and a conditioning chamber or tray the collections staff can service without opening the display volume. The access design and the sealing design are the same problem: every way into the case is a place the boundary has to close again, repeatably, for years of maintenance cycles.
Ventilated cases take the opposite bet: rather than trapping an interior atmosphere, they exchange it — slowly and through filtered paths, so dust does not ride in with the air. Here the fabrication questions become vent placement and concealment, filter access, and keeping the exchange passive and quiet so it never reads as a feature of the display.
In both patterns, the division of labor is clean: the conservator specifies the environmental behavior; the fabricator executes the construction that produces it.
Materials selection: disclosure, not certification
Institutions screen case materials through their own testing protocols — Oddy testing is the screening most collections professionals know by name, and many institutions maintain internal lists of materials that have passed or failed their own labs. A fabricator’s role in that system is specific and worth stating plainly:
- Disclose everything. A materials schedule for the build — glazing, adhesives, gaskets, sealants, deck materials, finishes — specific enough for the conservation department to screen against their protocols and records.
- Provide samples. The institution’s lab tests actual candidate materials — supplied for screening ahead of construction, on the institution’s protocol.
- Accommodate substitutions. When a component fails the institution’s screening, the build absorbs the change — that flexibility is part of what the institution is buying.
- Point to the manufacturer’s paper. Specifiers who want batch-level documentation should request the manufacturer’s data sheet and lot certificate for the sheet material in their spec, so the paper trail runs to the source.
What a fabricator should never do is assert that its materials are conservation-approved as a blanket fact. Screening results belong to specific materials, specific batches, and the institution’s own lab. The claim worth making is the working one: the materials in the build are disclosed completely, and the construction adapts to what the institution’s screening decides.
The construction details registrars ask about by name
Beyond materials, a handful of fabrication specifics come up in nearly every institutional case conversation:
- Joint quality, graded. Bonded seams on collection casework are judged close-up, which is why they should be specified against the published Acrylic Joint Clarity Standards rather than described with adjectives — a named grade makes the acceptance inspection decidable.
- Finish grade. Casework that visitors lean into is Museum Archival Finish territory under the Acrylic Quality Standards, whose Inspection Distance for that grade is approximately 1 foot — and the Edge Finishing Standards note that Museum Archival Finish projects often require diamond-polished edges.
- UV-filtering glazing. UV-filtering acrylic formulations are a specification option for light-sensitive collections; the institution’s lighting and conservation plan decides where they apply.
- Dust behavior at joints and access panels. Gasket and interface design determines whether a case stays clean between maintenance cycles — and machining precision at those interfaces is what makes a gasket actually seal.
- Barrier layers. Inert barrier films and liners between deck construction materials and the object are a standard accommodation where the deck build-up includes materials the conservator wants isolated.
How the collaboration runs on real projects
This way of working is not theoretical for us. Display casework built in this shop has gone to institutions including the Whitney Museum of American Art and the Johnson Museum of Art at Cornell University. Casework from the archive is in our project gallery.
If you are specifying a case for a collection, bring the conservation requirements to the conversation as early as the design intent — the construction decisions above are cheapest before anything is cut. Start with the object, and we will build the environment around it.
