Dear Thomas, I tested making my simpleslides module "SsuWave" by modifying "simpleslides-s-Rounded.tex" (1) I just replaced MP figures for horizontal and title with some figures as follows for test : \defineoverlay [simpleslides:background:horizontal] % [\useMPgraphic{simpleslides:MP:horizontal}] [\externalfigure[/Users/graph/Documents/figures/background/ssuwave1][]] \defineoverlay [simpleslides:background:title] % [\useMPgraphic{simpleslides:MP:title}] [\externalfigure[/Users/graph/Documents/figures/background/ssuwave][]] But it does not work. I got error as follows: ! Argument of \douseexternalfigure has an extra }. ..... 22 \stopitemize 23 24 >> \SlideTitle{벡터의 연산 } 25 .... <inserted text> \par <to be read again> } \pack_layers_set ...group \edef \currentlayer {#1} \edef \p_pack_layers_state... <to be read again> { \61>simpleslides:background:horizontal ...uwave1]{ \executedefinedoverlay {si... \pack_framed_process_background_indeed_external ... \else \kern -\framedbackgr... ... (2) In the log file, I checked that it was read during the process. mkiv lua stats > loaded tex modules - 6 requested, 6 found (*-animation *-simpleslides *-simpleslides-s-SsuWave *-units simpleslides-f-default simpleslides-s-default), 0 missing ... I think that it needs more job to do this. Would you please tell me any ideas? Thank you. Best regards, Dalyoung