Still trying to fix my problem with letter-spacing and fixed width spaces. Do I understand that correctly that XSL-FO's view of letter-spacing is different than, say, PDF's? PDF's character spacing (PDF 1.4, 5.2.1) is designed so it advances the cursor for each (!) character by the Tc value. FO on the other side applies half the letter-spacing value on the start and end side of the glyph, and only for the characters that are classified as "Alphabetic" by Unicode. And I don't even say anything about setting precendence and conditionality to anything else than the default.
The weird thing about this definition in FO is that these spaces are added (by default) in every case, i.e. even at the beginning of a line: ("|"=line boundaries, "_"=spaces generated by letter-spacing) (The text "text text text" is used with text-align-last="justify" here) letter-spacing="normal": |text text text| (Note: FOP does have the "permission" by the FO spec to increase the inter-character gap here but we don't right now.) letter-spacing="1pt": |_t__e__x__t_ _t__e__x__t_ _t__e__x__t_| PDF's character spacing would work like this, I think (although the last character space needs to be eliminated by the layout manager ): |t__e__x__t__ __t__e__x__t__ t__e__x__t|(__) <--  If I'm right here (not really sure, that's why I'm asking), it would mean that we should probably stop using the Tc feature from PDF and instead control the glyph positioning ourselves like we already do in PostScript. WDYT? Jeremias Maerki