Hi Hans, this is a bug report thanks to Khaled: http://tex.stackexchange.com/a/126650/14066 In short: the font loader applies the kerning of libertine version 5.3.0 even though this appears to be broken in the font. Context translation of the example: \definefontfeature [kerning] [mode=node,smcp=yes,kern=yes] \definefont [libertineserifsmallcaps] [file:LinLibertine_R.otf*kerning] \definefont [libertinesanssmallcaps] [file:LinBiolinum_R.otf*kerning] \def\demotext{Vacillate Vaccine Vapour Vanish Va...} \starttext {\libertineserifsmallcaps \demotext}\par {\libertinesanssmallcaps \demotext}\par \stoptext (Doesn’t occur in base mode.) The technical details are in the thread Khaled references. Best regards, Philipp -- () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments