Hans Hagen
alternative
\startuniqueMPgraphic{underline} numeric w,h; w := OverlayWidth; h := ExHeight/6; path p; p := (0, -h)..(w/2,0 + (h/3 randomized h/3))..(w, -h); draw p withpen pencircle scaled 1 withcolor OverlayColor ; setbounds currentpicture to unitsquare xyscaled (OverlayWidth,OverlayHeight); \stopuniqueMPgraphic
\defineoverlay[underline][\uniqueMPgraphic{underline}]
\def\aidul{\dosingleempty\doaidul} \def\doaidul[#1]{\inframed[background=underline,frame=off,#1]}
\setupcolors[state=start]
Thanks for the fast response and the many lines you've written (although I didn't understand everything). The OverlayColor works fine and as underlining is in the background, I'll take this aproach. So, one last question remains: why doesn't this work? \def\uli{backgroundcolor=peachpuff} \aidul[\uli]{test} bye, Adam.