The scope of labels in exhibits can vary widely, but broadly speaking most exhibit curators develop interpretive labels, or labels that help place the object on display within a larger socio-historical context of its time and/or its place in the current historical moment.
Introducing the exhibit
While they may vary slightly depending on the unique context and purpose of each exhibit, introductions set the scene by describing the exhibit as a unified whole. They may describe key elements of the social moment in which the objects on display were created, they may describe the intentions of the exhibit (or what they want visitors to gain from the experience), they may explain how viewers should move through the exhibit, or all of the above.
Identifying and explaining the item
Each item in the exhibit also needs to be described. At the most basic level, these item-level labels are a basic resource citation similar to the works cited list at the end of a research paper or book. As the need warrants, there may also be deeper contextualizing information, such as highlighting key details of the image on display that might be missed by the casual observer.
Want to know more about exhibit labels? Check out this fantastic book:
Exhibit Labels by 
Make no assumptions about your audience's existing knowledge. Write in plain but engaging language.
Do your research! In order to find and effectively highlight the significant aspects of your object, you need to know it inside and out. Depending on the overall goals of your exhibit, this may mean learning about how the object was built, the creator's biography, the symbolism, or cultural implications of key images or words in your object.
Want to know more about writing labels? Check out this detailed but concise guide to writing labels:
Greive, Kristine. Writing Exhibit Labels Handout (University of Michigan). https://docs.google.com/document/d/1QhSgmNYLA3rliVLoP1X6gNTx0pnCovCp5OkHVmod5PU/edit#heading=h.sib2kaaero45
Legibility for all viewers is the key. Font style and size will be important considerations in designing your labels. This is one part of a larger puzzle. The other pieces include how much information do you want to share/must share and how much space do you have in the exhibit space.
Font Point/Size - 14 point font at a minimum. 18 point font is better.
Why? you want your exhibit to be as accessible as possible to everyone. Simplifying the experience by making your font large enough to read easily means more people will actually read and engage with the text and the object. Larger fonts may also be preferred by some readers with dyslexia.
Font Type - Many accessible design sources recommend a san serif font, such as Verdana, Arial, etc.
Why? These fonts clearly distinguish between upper and lower-case letters, and the absence of decorative details make it easier for readers of all vision-levels to recognize. These fonts are also less crowded, and may be preferred by some readers with dyslexia.
Want to know more about accessible design for print? Check out the following resources:
"Accessible Typography." APA Style. https://apastyle.apa.org/style-grammar-guidelines/paper-format/accessibility/typography
"Clear Print Guidelines. Ontario's Universities Accessible Campus. https://accessiblecampus.ca/reference-library/accessible-digital-documents-websites/clear-print-guidelines/
"Creating a Dyslexia Friendly Workplace." British Dyslexia Association. https://www.bdadyslexia.org.uk/advice/employers/creating-a-dyslexia-friendly-workplace/dyslexia-friendly-style-guide
