Hans, I added lfbd values for GFS Didot (attached) to get hanging diacritics in Greek. The attached PDF document is the optput from the following code: \showframe \setuplayout[topspace=1cm, height=middle, footer=0cm, header=0cm] \definefontfeature[default][default] [protrusion=quality, opbd=yes, script=grek] \definefontfamily[mainface][rm][GFS Didot] \setupbodyfont[mainface, 325pt] \setupalign[hanging] \starttext Α\\Ἀ\\Α\\Ἁ\\Α\\Ἂ\\Α\\Ἃ\\Α\\Ἄ\\Α\\Ἅ\\Α\\Ἆ\\Α\\Ἇ Ἐ\\Ε\\Ἑ\\Ε\\Ἒ\\Ε\\Ἓ\\Ε\\Ἔ\\Ε\\Ἕ\\Ε Ἠ\\Η\\Ἡ\\Η\\Ἢ\\Η\\Ἣ\\Η\\Ἤ\\Η\\Ἥ\\Η\\Ἦ\\Η\\Ἧ\\Η Ἰ\\Ι\\Ἱ\\Ι\\Ἲ\\Ι\\Ἳ\\Ι\\Ἴ\\Ι\\Ἵ\\Ι\\Ἶ\\Ι\\Ἷ\\Ι Ὀ\\Ο\\Ὁ\\Ο\\Ὂ\\Ο\\Ὃ\\Ο\\Ὄ\\Ο\\Ὅ\\Ο Ρ\\Ῥ Ὑ\\Υ\\Ὓ\\Υ\\Ὕ\\Υ\\Ὗ\\Υ Ὠ\\Ω\\Ὡ\\Ω\\Ὢ\\Ω\\Ὣ\\Ω\\Ὤ\\Ω\\Ὥ\\Ω\\Ὦ\\Ω\\Ὧ\\Ω \stoptext BTW, to get pure lfbd values, I had to replace line 361 from font-imp-quality lua with: local p = d/1000 Raw lfbd and rtbd values from the font could be set with protrusion=opentype (or a similar option). I hope it is clear now why raw values from the font are needed. Many thanks for your help, Pablo -- http://www.ousia.tk