Hi Meghan,
Thank you for reaching out to C2C Care! I've contacted a couple of our experts who have more experience with textiles, and also to someone who may have more plastics experience. One expert noted that the vinegar smell was odd and unexpected, 100% polyester and the canvas are very stable materials and shouldn't be off-gassing acetic acid. It may be from the vinyl breaking down or from the printing ink.
Her recommendation is as follows:
Yes, rolling these would be most likely a good way to store them. Best practice is only one per tube. If they can't do that, then they need to be rolled sequentially, with washed muslin, washed soft Tyvek, or acid-free paper as barriers between one banner and the next. They should not be rolled as a pile. She didn't mention if any have any hardware for hanging/use. If they do, this end will be bulkier than the rest. To roll them evenly (even if just one on a tube), she can pad out the part below the hardware with polyester batting, separated from the banner by any of the materials just mentioned.
She mentioned also that deaccessioning is outside her experience, but would hesitate to deaccession any unless they were truly duplicates.
Personally, are the banners from protests and demonstrations in the United States? If so, I can put you in touch with the American Folklife Center here at the Library of Congress to see if they could give you more information. We have several banners across different divisions in our collections, so depending on where the banners are from I could direct you to the right librarian.
All the best,
Liz
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Elizabeth Peirce
C2C Care Community Monitor 7/21-8/3
Conservator (Objects)
Library of Congress
Washington DC
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