Wityh this working example: \starttext The quick brown fox jumped over the lazy dog \definefontfeature [effect-widen] [effect={width=.2,delta=0.3}] \definedfont[Sans*widen,effect-widen] The quick brown fox jumped over the lazy dog \stoptext I am puzzling to turn my working \definedfont into a \definefont so I can use that instead. Actually, my setup is Optima with Helvetica used for Cyrillic: \definefallbackfamily [archimate] [ss] [Helvetica] [preset=range:cyrillic, tf=style:light, it=style:lightoblique, bf=style:regular, bi=style:oblique, force=yes, rscale=1.0] \definefontfamily [archimate] [ss] [Optima] \setupbodyfont[archimate] And I would like the effect to work on just the Optima font (which is a bit light for this use) I’ve been trying to work out using \definefont with the effect but have so far failed. Thanks, G