I am automating the creation of books using ConTeXt with a graphic design graduate student at the Rhode Island School of Design. The book cover is created using MetaPost inside a ConTeXt source file. The graphic designer tells me it is very common to specify the interletter spacing, or tracking, and in fact, he considers this capability to be essential. I understand that these, so called, microtypography capabilities are present in pdfTeX fully, but only partially present in LuaTeX (protrusion and expansion), although tracking can be set in a way using \kerncharacters[0.5] in LuaTeX. However, the quality of the typesetting produced by LuaTeX is completely inadequate, while the quality of the typesetting produced by pdfTeX is very good. Am I miss-understanding the differences in capability between pdfTeX and LuaTeX in this regard? Relevant examples follow and PDFs are attached. I processed the following ConTeXt source file using MKII: This is pdfTeX, Version 3.1415926-1.40.10 (Web2C 2009) (format=cont-en 2011.8.13) ConTeXt ver: 2011.05.18 18:04 MKII fmt: 2011.8.13 int: english/english ===== START MKII EXAMPLE ===== \pdfminorversion=5 \definepapersize[LG1][width=9.3in,height=6.87in] \definepapersize[LP1][width=9.55in,height=7.12in] \setuppapersize[LG1][LP1] \setuplayout[location=middle,marking=off] \setuppagenumber[state=stop] \startMPenvironment \usetypescript[modern][ec] \switchtotypeface[modern][7.0pt] \setupinterlinespace \def\stretchedspacefactor{4} \def\stretchedspaceamount{0.25em} \stopMPenvironment \startuniqueMPgraphic{cover} cover_paper_width := 9.55in; cover_paper_height := 7.12in; left_margin := 0.347222222222in; top_margin := 0.347222222222in; bottom_margin := 0.347222222222in; draw (0, 0)--(cover_paper_width, cover_paper_height) withpen pencircle scaled 1bp withcolor white; picture labelText; labelText := btex {\vbox{\hsize 2.38888888889in \baselineskip 10.5pt T\hskip 0.25em\stretchednormalcase{HIS BOOK CONTAINS 988 TWEETS POSTED TO TWITTER BY LADYGAGA FROM MARCH 27, 2008 TO AUGUST 5, 2011. IT WAS PUBLISHED ON DEMAND ON AUGUST 14, 2011}}} etex; labeloffset := 0bp; label.lrt(labelText, (left_margin, cover_paper_height - top_margin)); \stopuniqueMPgraphic \defineoverlay[cover][\uniqueMPgraphic{cover}] \starttext \title{} \setupbackgrounds[paper][background={cover}] \stoptext ===== STOP MKII EXAMPLE ===== I processed the following ConTeXt source file using MKIV: this is luatex, version beta-0.70.1-2011051908 (rev 4277) ConTeXt ver: 2011.05.18 18:04 MKIV fmt: 2011.7.13 int: english/english ===== START MKVI EXAMPLE ===== \pdfminorversion=5 \definepapersize[LG1][width=9.24in,height=6.87in] \definepapersize[LP1][width=9.49in,height=7.12in] \setuppapersize[LG1][LP1] \setuplayout[location=middle,marking=off] \setuppagenumber[state=stop] \definefont[LabelFont][Serif sa 0.583] \startuniqueMPgraphic{cover} cover_paper_width := 9.49in; cover_paper_height := 7.12in; left_margin := 0.347222222222in; top_margin := 0.347222222222in; bottom_margin := 0.347222222222in; draw (0, 0)--(cover_paper_width, cover_paper_height) withpen pencircle scaled 1bp withcolor white; picture labelText; labelText := btex {\vbox{\hsize 2.38888888889in \baselineskip 10.5pt \LabelFont {\kerncharacters[0.5] THIS BOOK CONTAINS 988 TWEETS POSTED TO TWITTER BY LADYGAGA FROM MARCH 27, 2008 TO AUGUST 5, 2011. IT WAS PUBLISHED ON DEMAND ON AUGUST 14, 2011}}} etex; labeloffset := 0bp; label.lrt(labelText, (left_margin, cover_paper_height - top_margin)); \stopuniqueMPgraphic \defineoverlay[cover][\uniqueMPgraphic{cover}] \starttext \title{} \setupbackgrounds[paper][background={cover}] \stoptext ===== STOP MKVI EXAMPLE ===== The MKII PDF The MKIV PDF