local f = GameTooltip
f:SetBackdrop{
    bgFile = "Interface/Tooltips/UI-Tooltip-Background",
    edgeFile = "Interface/Tooltips/UI-Tooltip-Border", 
    tile = false, 
    tileSize = 6, 
    edgeSize = 18, 
    insets = { 
        left = 4, 
        right = 4, 
        top = 4, 
        bottom = 4
    }
}
f:SetBackdropColor(0,0,0,.8)
f:SetBackdropBorderColor(0,0,0,1)