Haven't really heard of this, but it is a fresh new gimmick to add to the already fascinating allure of vinyl records- check this out from a post on Pitchfork.com
"We wouldn't ordinarily advocate scratching your vinyl, but in this case, we'll make an exception. Black Moth Super Rainbow, the convention-thwarting Pennsylvanian bunch responsible for last year's Recommended Dandelion Gum album, have gone and pressed said release into a turntable-ready LP.
Okay nothing so unconventional there, but wait! This isn't just any vinyl we're talking about here. This is, as you may have noticed in the headline, scratch'n'sniff vinyl!! Yes, the friction created by running something coarse (a fingernail, say) across the cover of this record will unleash odors as yet un-smelt by the noses of men! Women, too!
As if this olfactory offering weren't enough, the vinyl version of Dandelion Gum also includes a bonus track not found on the CD, "The Dark Forest Joggers". Both formats are available now via Graveface Records."