For some time now I have been partially aware of some oddities in the XeTeX implementation of :letterspace, but it was only today that my thoughts crystallised sufficiently for me to attempt to record them on- list :
1) Search functionality. For : \font \errorfont = "Copperplate Gothic Bold:letterspace=8,color=BF0000" scaled 2260 \newbox \errorbox \setbox \errorbox = \leftline {\errorfont +++ NOT AT TOP OF PAGE +++} Adobe Acrobat 7.1 has no problem locating the string "+++" if the contents of \errorbox end up in the PDF file; however, for \font \errorfont = "Copperplate Gothic Bold:letterspace=16,color=BF0000" scaled 2260 the same string cannot be found. 2) \fontdimen 2 is not affected by the :letterspace parameter; arguably it should be, such that interword space is stretched in proportion to interletter space (and perhaps \fontdimens 3, 4 & 7 should be modified as well, and perhaps even 6). -- Philip Taylor
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