I wonder how I can get crop marks to work. This is what I have, but they don't show:

%=== MWE =====

\definepapersize[Labelpaper][width=95mm,height=90mm]
\setuppapersize[Labelpaper][A4,portrait]

\setuplayout[
    backspace=3mm,
    margin=0mm,
    topspace=3mm,
    header=0mm,
    footer=0mm,
    width=89mm,
    height=84mm,
    nx=2,
    ny=3,
    location=middle,
    marking=on   % according to the wiki,