One problem left with dimensions that I can’t reproduce in a minimal example: I want to calculate the spine width of the cover from the number of content pages: \useexternalfigure[CONTENT][book.pdf] \getfiguredimensions[CONTENT] \definemeasure[SpineWidth][2mm + (0.135mm * \noffigurepages/2)] That works so far, if I output \measure{SpineWidth} it shows the right size (~42pt). But if I use this measure in \setlayer[width=\measure{SpineWidth}]{...} it’s very small. I guess \noffigurepages is 1 at that point (from another image) and I’d need to expand it first. Am I right that the expansion happens only at the “execution” of \measure? How would I do that? \expanded\noffigurepages doesn’t work. Another issue: 0.135mm is the paper thickness of 90 g/m² (= 0.09mm per sheet) with 1.5 bulk. But \definemeasure[SpineWidth][2mm + (0.09mm * 1.5 * 90)] doesn’t work: """ Missing ) inserted for expression <to be read again> . <macro> \commalistcommand 2mm + (0.09mm * 1. 5 * \noffigurepages /2) <macro> \measured #1->\dimexpr \ifcsname \??measure #1\endcsname \lastnamedcs \else \zeropoint \fi \relax ... """ I also tried 1.5sp since sp should be 1, but it didn’t help. Hraban