Hello Lukáš, I don't understand layers and overlays. This is what I could learn about \tightlayer from the source; I hope that reviving your question will help somebody else actually answer it. \tightlayer is defined in pack-lyr.mkiv. \unexpanded\def\tightlayer[#1]% {\hbox {\def\currentlayer{#1}% todo: left/right \setbox\nextbox\emptybox % hoogte/breedte are \wd\nextbox/\ht\nextbox \hsize\layerparameter\c!width % \overlaywidth = \hsize \vsize\layerparameter\c!height % \overlaywheight = \vsize \composedlayer{#1}}} The last command flushes the layer we are about to place: \composedlayer{x} is syntactic sugar for \flushlayer[x]. (Braces vs. brackets.) So it seems that what \tightlayer does is create a layer object exactly as large as its contents? What this is good for, and how it relates to overlays, I do not know. Good luck! --Sietse