I have a document in which left and right cannot be equated with inner and outer respectively (outside the header texts). So I use \setuppagenumbering[alternative={singlesided,doublesided}]. But I still need a gutter along (what would be) the inner margin. So, how would I go about duplexing a single-sided layout? For example: \definepapersize[custom][width=335mm,height=500mm] \setuppapersize[custom][B3] \setuplayout[% width=middle,% height=middle,% backspace=90mm,% topspace=25mm,% leftmargin=30mm,% rightmargin=15mm,% leftmargindistance=5mm,% rightmargindistance=20mm,% location={doublesided,duplex},% bottomspace=25mm,% cutspace=90mm] \setuppagenumbering[alternative={singlesided,doublesided}] Sincerely yours, Adam Khan