Methods for processing print jobs in rendering devices include modifying a raster operation function to have fewer variables than originally specified by the print job. Processing may also include executing the modified function and determining how many variables the function originally includes and whether such is one or more. Preferably, the modifying of the function includes determining whether a variable of the function has a black or white identity, such as a black or white ink or a black or white image, stencil or character. It may also include determining whether a destination variable remains unaltered in a to-be-painted area. Printers having stored computer executable instructions for performing the steps are also disclosed as are host devices that may direct or control the printer to perform the same.