Editing WoW:XML/BackdropTemplate (section)

=== 'backdropInfo' table options ===
''which must be defined outside of FrameXML in Lua''
* bgFile (string) - the resource path to the backdrop background texture
* edgeFile (string) - the resource path to the backdrop edge texture

* tile (boolean) - if background is tiled, true to tile
* tileEdge (boolean) - if the top, bottom, right, left edge texture components are tiled, true to tile

* tileSize (number) - default is 32. the size of section of the texture to use for the background when tiled, starting at x,y 0,0 to a width and height of 'tileSize'. the top rendered row will repeat the tiled portion of the texture, while the remainder of the background will only use the bottom row of pixels of the tile, to repeat as tiles to the bottom of the background area.
* edgeSize (number) - default is 32. width and height of texture source and drawn edge pieces

* insets (table) - the edge and background rendering offsets relative to the natural bounding box of the frame. like, 'insets = { left = 3, right = 5, top = 3, bottom = 5 },'
** left (number) - left edge inset amount toward the right
** right (number) - right edge inset amount toward the left
** top (number) - top edge inset amount toward the bottom
** left (number) - bottom edge inset amount toward the top