Signed vinyl lives in a poly sleeve, not the original shrink.
Put it in a poly outer sleeve and a rice paper inner sleeve immediately. That’s the whole trick.
The original shrink wrap will eventually shrink more, warping the cover. And the standard paper inner sleeve will leave scratch marks over time. A poly outer sleeve (the kind with a flap, not the tight ones) keeps dust off and prevents corner dings. A rice paper or anti-static inner sleeve protects the record itself when you slide it in and out.
Store the whole thing vertically, like a book, in a cool, dark spot. Never stack records on top of each other — that bends sleeves. And keep it away from radiators or direct sunlight. Signed covers are sentimental, so treat them like a collectible, not just a record.
Future you will thank you when the signature is still crisp and the cover looks new.