Here's an excerpt from a previous article, in response to a question about displaying OA:
https://comicbookinvest.com/2016/12/30/first-appearances/
As with comic books, OA should be stored and displayed away from UV light, in stable cool and dry conditions.
The black India ink used in OA is usually lightfast (doesn’t fade in UV light) and permanent (waterproof once dry). Grey pencil graphite is typically lightfast as well, but can be smudged via physical contact. Watercolour and acrylic paint can be affected by UV light. Marker ink generally discolours and fades over time. OA is normally done on Bristol board, which is a hardy thick paper, but should be kept away from UV light to prevent yellowing.
When framing OA (or any art), make sure the artwork is not in contact with the glass/acrylic cover. In order to do this, place a mat border on top of the artwork or “float” the glass/acrylic above the artwork. Also ensure that all framing methods and materials used are of archival standards, and that materials in direct contact with the artwork are acid-free. The glass/acrylic used should be UV-filtering to minimize UV damage to the art and paper.