Hello list, i noticed that setting a different kerning breaks some features of opentype fonts; that is true, for example, for ligatures and fractions (frac feature). It looks like a modified kerning inserts something between two adjacent character, making them no more adjacent. That way the lookup of opentype tables fails. "f", "l" => "fl" ligature glyph "f", [kerning], "l" => distinct "f" and "l" glyphs "1", "/", "4" => "ΒΌ" glyph (with "frac" feature switched on) "1", [kerning], "/", [kerning], "4" => distinct "1", "/", "4" glyphs (always with "frac" feature switched on) MWE: \definecharacterkerning[narrow][factor=-.015] \definecharacterkerning[wide][factor=.015] \definefontfeature[frac][frac=yes] \starttext \feature[+][frac]% Some ligatures: float, finance, affine; a fraction: 1/4. \setcharacterkerning[narrow]Some ligatures: float, finance, affine; a fraction: 1/4. \setcharacterkerning[wide]Some ligatures: float, finance, affine; a fraction: 1/4. \stoptext In my XML to PDF workflow, fractions are marked up, so it's easy to switch the kerning off only for them. Instead i have no solution for ligatures: parts of text with a modified kerning loose ligatures, and i end up with the same words, once with ligatures, once without, even in the same page. Is there a workaround for this? Massimiliano