From the source of the manual: \starttext bar\par \blank[2\bodyfontsize] bar \stoptext with latest minimal I get: [...] system > tex > error on line 8 in file zz.tex: Illegal unit of measure (pt inserted) ... 1 \starttext 2 bar\par 3 \blank[2\bodyfontsize] 4 bar 5 \stoptext 6 <to be read again> ^^H <argument> 2^^H odyfontsize \addaskedblankskip ...nce \blankskip #1\dimexpr #2 \relax l.8 } \dovspacingyes ...#1\else \currentvspacing \fi ")} \fi l.3 \blank[2\bodyfontsize] [...] Herbert