I’ve tried searching for everything even remotely related to this issue and I found nothing. Neither information that it can’t be done nor anything saying that it would be different than setting custom headers for any other file. _headers /backgrounds/* Cache-Control: public, max-age=31536000 …

Custom headers for Large Media

Pentiado January 6, 2020, 12:03pm 7

That is unfortunate but thanks for info.
Anyway, I’m glad I found an issue that resolving will make Netlify better : )

Confusing headers behaviour

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