The microtype package

MICRO FINE TUNING: Tracking 15stretch, shrink and step, their respective global value will be used (that is, nocalculation will take place).As a practical example, suppose you have a paragraph containing a widow thatcould easily be avoided by shrinking the font a little bit more. In conjunction withthe context option (see section 6 for further details), you could thus allow formore expansion in this particular paragraph:\SetExpansion[ context = sloppy,stretch = 30,shrink = 60,step = 5 ]{ encoding = {OT1,T1,TS1} }{ }% ... END PREAMBLE{\microtypecontext{expansion=sloppy}%This paragraph contains an `unnecessary' widow.}This method of employing contexts to temporarily apply different expansion parametersonly works with pdfTEX version 1.40.4 or later (for older versions, a dirtytrick is laid out in section 14.2 on page 56). Also note that pdfTEX prohibits theuse of fonts with different expansion limits or steps (even of different fonts) withinone paragraph, hence the sloppy context has to be applied to complete paragraphs.factor This option provides a different method to alter expansion settings forcertain fonts, working around the restriction just mentioned. The factor optioninfluences the expansion factors of all characters (in contrast to the overall stretchability)of the font. For instance, if you want the italic shape to be expanded less,you could declare:\SetExpansion[ factor = 500 ]{ encoding = * ,shape = it }{ }The factor option can only be used to decrease the stretchability of the characters,that is, it may only receive values smaller than 1000. Also, it can only be used forsingle fonts or font sets; setting it globally in the package options wouldn’t makemuch sense – to this end, you use the package’s stretch and shrink options.5.3 Tracking pdfTEX 1.40 | LuaTEX 0.62\SetTracking[〈options〉] {〈set of fonts〉} {〈tracking amount〉}An important typographic technique – which was missing in TEX for a long time – isthe adjustment of tracking, i.e., the uniform addition or subtraction of letter spaceto/from all the characters in a font. For example, it is good typographic practiceto slightly space out text set in all capitals or small capitals (as in this document).Legibility may also be improved by minimally increasing the tracking of smallerand decreasing that of larger type. 6 The \SetTracking command allows specifying6 With full-featured fonts like Computer Modern, this is usually not necessary, though, since they come inoptical sizes, and the tracking of the small-capitals font is already adjusted.