Hi, I'd like to increase the backspace at the expense of the makeupwidth. I like to do this by adding either a scalar or a percentage of the backspace. In the following bit of code I'd expect both sets of \mybackspace and \mywidth macros to yield identical results, but the don't. The scalar approach seems to work correctly, and the percentage not. I'd appreciate it if somebody could show me where I've gone wrong. It must be embarrassingly simple, but I can't see it - yet. Thanks in advance. Cheers, Michael \showgrid \showframe %\showlayout \def\abcor{1.25cm} % absolute binding correction \def\pbcor{0.5} % percentage binding correction % default backspace is 2.5cm %\def\mybackspace{\dimexpr(\backspace + \abcor)} \def\mybackspace{\dimexpr(\backspace + \pbcor\backspace)} % default makeupwidth is 15cm %\def\mywidth{\dimexpr(\makeupwidth - \abcor)} \def\mywidth{\dimexpr(\makeupwidth - \pbcor\backspace)} \setuplayout [location=middle, backspace=\mybackspace, width=\mywidth] \starttext \dorecurse{10}{\input tufte \par} \stoptext