Hi, for an involved image placement (full page image starting each chapter, several stacked elements), I’d like an environment that accepts key-value arguments, like \startMyFigure[page=left,title={My caption}] \externalfigure[dummy]… \stopMyFigure I don’t think that a real float makes sense, even if the interface looks similar, since it’s always a full page in a fixed place, I need no numbering and can place the caption myself. Does it make sense to use \definestartstop? How would I “plugin“ the argument handling? Or should I better define start and stop separately? \def\startMyFigure[#1]{ % e.g. use utilities.parsers.settings_to_hash(#1) } \def\stopMyFigure{} Probably I’ll need to catch the content (\externalfigure, might become more) and use it in a \setlayer – so perhaps something like \definebuffer[MyFigure] \define\stopMyFigure{% \setlayer[page]{\getMyFigure}}} } ? But then I don’t know how to handle the arguments. Probably it makes most sense to do it in Lua, like \startluacode interfaces.implement { name = "startMyFigure", public = true, arguments = {"hash",}, actions = function(h, a) -- … end, } \stopluacode But I didn’t find how to do environments. Hraban