Meguiars Scratch-X. Sounds strange to use it, but it cleans off all the grime, makes the picture look better, and leaves a very mild odor. Works ONLY on smooth 'hard' paper, or coated covers. (forget the soft fuzzy paper covers!)
On a very few LP covers, It seems to interact with some other product on/in the coating, then I just clean it off with a damp cloth/paper towel after using. I use Viva paper towels: they are the closest to a soft cloth.
The great thing about Scratch-X is that it lessens the mottled markings of wear on most glossy covers, like ring and label area wear on a cover.
On a very few LP covers, It seems to interact with some other product on/in the coating, then I just clean it off with a damp cloth/paper towel after using. I use Viva paper towels: they are the closest to a soft cloth.
The great thing about Scratch-X is that it lessens the mottled markings of wear on most glossy covers, like ring and label area wear on a cover.