Pink Floyd’s Wish You Were Here was originally packaged in dark blue shrink wrap; you couldn’t see the album cover until you bought it.
Gatefold covers eventually became routine, but when the Beatles did one for Sgt. Pepper, it was highly unusual. They were logical for double albums (since they could hold two records), but they quickly became used on single disks.
Including copies of legal papers and contracts --most notably for Woodstock-- that have embarassed people on Antiques Roadshow and Pawn Stars. (Not to mention my co-worker, who was extremely excited when he presented a Woodstock contract to me that he found in a record bin at a Goodwill store. :p)
The first pressings of The Return of the Durutti Column had a cover made of sandpaper, designed to destroy the covers of LPs it was shelved next to (scroll down for a picture, for what it’s worth). A joke inspired by this book, apparently.
And the blank spots on the album in that link are the result of the pictured people (or their estates) suing the band because their images were used without permission.
The Alan Parsons Project’s *Stereotomy *originally came in a regular sleeve with blue and red artwork on it (kind of like an old 3D image), but then the whole thing was packaged in a plastic slipcover that was transparent red on one side and blue on the other. Slipping the album inside the slipcover revealed different images. It was pretty cool.
My copy’s tearoff was a foldout calendar for 1972 with Alice hung from a rope at the top. It was set up sort of like a double album cover except the one half was meant to be torn off and itself unfolded.
I think it was Billion Dollar Babies that had the postcards, wasn’t it? (I never owned either one of those albums on vinyl. I did have School’s Out with the desk-shaped gatefold, but my copy had a plastic inner sleeve instead of the infamous panties.)
Captain Beyond’s debut self-titled LP from 1972 did feature a hologram cover, though. I don’t know of any hologram cover which antedates it. Come to think of it, I don’t know any any other hologram covers at all.
More in the “unusual for the time” category, but the Rubber Soul jacket did not include the name of the band that recorded it, and Blonde on Blonde featured a photo that was very obviously out of focus.
Not that young - I’m 36, and have smoked a LOT of weed in my time. “Grass,” however, is not a term that I think I’ve ever used. I honestly thought you were talking about your lawn.