How Museums Decide What To Exhibit
Exhibitions are planned years ahead, and the constraints are practical long before they are curatorial.
A major exhibition is typically planned several years in advance. Understanding why explains a great deal about what appears on museum walls and what does not.
Loans take years
Most exhibitions depend on works borrowed from other institutions and private collections. Loan requests are made well ahead, negotiated individually, and can be refused.
Lending institutions consider the condition of the work, whether it is required for their own displays, the borrower's environmental and security standards, and reciprocity. A single refusal can require an exhibition to be reconceived.
Condition governs
Some works cannot travel. Fragile media, large or structurally vulnerable objects, and works on paper with cumulative light exposure limits are frequently immovable.
This is why certain famous works never appear in touring exhibitions, and it is a conservation judgement rather than an institutional reluctance.
Insurance and indemnity
Insuring borrowed works of significant value is expensive, and government indemnity programs exist in several countries to reduce that cost for qualifying exhibitions. Access to such a program can determine whether a show is financially possible.
Funding
Large exhibitions are usually supported by sponsors, foundations or individual donors, and fundraising happens during the planning years. Institutions have policies governing what a sponsor may and may not influence, and the credibility of those policies is a live subject in the field.
Space and sequence
Museums have a fixed number of temporary exhibition spaces and each must be programmed continuously. A slot committed to one exhibition is unavailable for years, which makes scheduling a genuine constraint on what can be shown and when.
What this means for a visitor
An exhibition assembling major loans from many lenders represents years of negotiation and will not recur. Shows drawn primarily from a museum's own collection are more easily mounted and more likely to return in some form.
Knowing which you are looking at is a reasonable guide to what is genuinely worth rearranging your week for.