Hi Hans, when you process the following example you can see that the layer box is positioned in MkII at the top of the page but in MkIV at the bottom, why has this changed? \definelayer[test][width=\paperwidth,height=22mm,option=test] \setlayer[test][x=104mm,y=11mm]{\externalfigure[cow][width=56mm]} \setupbackgrounds[page][background=test] \starttext Hello \stoptext The change happened in this code block where you moved \vss from the bottom of the box to the top: \def\pack_layers_flush_indeed#1#2% quite core, so optimized {\begingroup % already grouped ... \ifx\p_pack_layers_option\v!test \ruledvbox \else \vbox \fi \ifx\p_pack_layers_method\v!overlay to \overlayheight \fi \layoutcomponentboxattribute {\vss \hbox \ifx\p_pack_layers_method\v!overlay to \overlaywidth \fi {\box\nextbox \hss}% }%\vss}% ... \endgroup} Wolfgang