Hello Bart, Try \starttypescript[serif][caslon][uc] \definefontsynonym[CaslonRegular][name:CaslonOldFaceBT-Roman][encoding=uc] \definefontsynonym[CaslonItalic][name:CaslonOldFaceBT-Italic][encoding=uc] \definefontsynonym[CaslonBold][name:CaslonOldFaceBT-Heavy][encoding=uc] \stoptypescript \starttypescript[serif][caslon][name] \definefontsynonym [Serif] [CaslonRegular] \definefontsynonym [SerifItalic] [CaslonItalic] \definefontsynonym [SerifBold] [CaslonBold] \stoptypescript \starttypescript[caslon][uc] \definetypeface[caslon][rm][serif][caslon][default][encoding=uc] \stoptypescript \usetypescript[caslon][uc] \setupbodyfont[caslon, 12pt] \starttext Testing {\bf Testing} {\it Testing} \stoptext Note the two changes: \definetypeface's in the first typescript have been replaced with \definefontsynonym commands, and the font names have been prepended with "name:", forcing XeTeX to look for an installed font instead of a TFM (in plain XeTeX, you get the same result by surrounding the font name with double quotes). I am unable to test the typescript because I don't have Caslon Old Face, but it works when I replace the font names with the appropriate faces from Adobe Caslon, which I have. Arthur