a computer implemented method includes the steps of : a ) generating a template pdl specification , the template specification including template data and associated graphic attributes defining how the template data is to appear on a printed page , the template specification including at least one variable data identifier ; b ) generating a plurality of sub - template pdl specifications , each sub - template specification including sub - template data and associated graphic attributes defining how the sub - template data is to appear on a portion of a printed page ; c ) interpreting the template specification so as to generate a template bitmap or a plurality of template rendering commands , and during the interpreting step , identifying the variable data identifier ; d ) saving the template bitmap or the plurality of template rendering commands into memory ; e ) associating the variable data identifier with the sub - template specifications ; f ) accessing a first sub - template specification from the plurality of sub - template specifications ; g ) processing the first sub - template specification so as to generate a sub - template bitmap or a plurality of first sub - template rendering commands ; h ) accessing a copy of the template bitmap or the plurality of template rendering commands from memory ; i ) merging the copy of the template bitmap or template rendering commands with the sub - template bitmap or sub - template rendering commands so as to provide a first merged bitmap or first merged plurality of rendering commands ; j ) generating a first merged bitmap from the first merged plurality rendering commands ; k ) accessing a next sub - template specification from the plurality of sub - template specifications ; l ) processing the next sub - template specification so as to generate a next sub - template bitmap or plurality of next sub - template rendering commands , m ) accessing a copy of the template bitmap or template rendering commands from memory ; n ) merging the copy of the template bitmap or template rendering commands with the next sub - template bitmap or sub - template rendering commands so as to provide a next merged bitmap or next plurality of rendering commands ; and o ) generating a next merge bitmap from the next merged plurality of rendering commands , if necessary . the steps k - o may be repeated , as necessary , to generate a plurality of merged bitmaps .