The MAME Artworks are * backdrops: specify the attributes of elements that are drawn first and which cover the background of the screen areas; they are rendered against each other using regular alpha blending, so they can have cut-out areas and other effects * screens: specify the attributes of the various screens that make up a game; they are referenced by index, and are rendered on top of the backdrop layer using additive blending (alpha values applied to the source but not the destination) * overlays: specify the attributes of elements that are drawn over top of the screens and backdrops; they are rendered on top of the screens and backdrops using RGB multiplicative blending (the RGB values of the overlays are multiplied by the RGB values of the destination) * bezels: specify the attributes of elements that are drawn last, over all the other elements; they are rendered using regular alpha blending, like the backdrops were.

Artwork Packs (Official) (1,545 zips) - Latest dat here

Artwork Packs (Alternate, Various authors) (335 zips) - Latest dat here.

Artwork Packs (16:9 WideScreen, Various authors) (3,825 zips) - Latest dat here.