Hi, Based on suggestions from Akira TAGOH, I propose another API for this purpose. Take an example which we plan to override "fontfeatures" and "fontfeatures" properties: customfont = FcDirCacheBeginCustomFont(config, file, index, stylename); FcCustomFontModifyString(customfont, FC_FONT_FEATURES, features); FcCustomFontModifyString(customfont, FC_FONT_VARIATIONS, variations); FcDirCacheEndCustomFont(customfont); Thanks, Peng _______________________________________________ Fontconfig mailing list Fontconfig@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/fontconfig