Thomas Fehige
8. Juni 2016 um 10:35
Nevertheless, I prefer to keep all the font and fontsize definitions and tweaks together in the preamble. This poster is not the only work I'm planning to do in ConTeXt, and I need to learn to swim while already in the water ;) .
For short texts where you want a certain style and size (e.g. a title page or a poster with few words) \definedfont is the recommended method, for larger amounts of the text (e.g. the abstract of a book) you can use \switchtobodyfont to change the size.
Meanwhile I found the command \definebodyfontswitch and defined switches like \normalsize, \scriptsize, \large, \Large etc.
The \definebodyfontswitch creates only a command which uses \switchtobodyfont with a fixed number of arguments.
But this doesn't explain why \definebodyfontenvironment did not do anything in my MNWE. The fonts book is not very clear on its intended use.
You put spaces before and after = which aren’t allowed there.

\definebodyfontenvironment
  [24pt]
  [         small=22pt,
              big=28pt,
                x=22pt,
               xx=16pt,
                a=30pt,
                b=40pt,
                c=50pt,
                d=60pt,
   interlinespace=30pt,
               em=italic]

\setupbodyfont[palatino,24pt]

\starttext

\startlines
 \tf   tf
{\tfa  tfa}
{\tfb  tfb}
{\tfc  tfc}
{\tfd  tfd}
{\tfx  tfx}
{\tfxx tfxx}
\stoplines

\stoptext

Wolfgang