Hello list,
I'm using the Adobe Garamond Premier Pro font.
It has 4 optical sizes: Caption, Normal, Subhead, Display.
I tried to modify ebgaramond.lfg to adapt it to Garamond Premier Pro.
You find it as an attachment.

I don't know how to use that goodies file to see the different optical sizes
in a document. I've tried this:

\loadfontgoodies[GaramondPremierPro]

\definefontfamily [default] [rm] [tf=name:GaramondPremierPro-Regular,
                                  it=name:GaramondPremierPro-Italic]

\setupbodyfont[default,12pt]

\dostepwiserecurse {6} {22} {1} {
  \definebodyfontenvironment[default][#1pt][text=#1pt,em=italic]
}

\starttext

    \dostepwiserecurse {6} {22} {1} {
        \switchtobodyfont[#1pt]
        \purefontname\font: \input tufte
        \blank
    }

\stoptext

but it does not work. Any help?
Thanks in advance, Massi

To Hans: if you find it useful for Context, you can add and/or modify it
to the distribution. You can also change the author to yourself.