Hello, Werner:
Have you tried some diagnostic tests, such as trying to get the PDF output via DVIPS? I suspect that you are, in fact, more knowledgeable and experience with ConTeXt than I am, but for what it is worth you may want to look at:

• \setupoutput[dvips,acrobat] (see: Context-The Manual (Hans Hagen; English, page 24))
• \showbodyfont[Options] (see: Not-so-short Intro to ConTeXt (J. Ataz-Lopez;English, page 114))
• $ mtxrun  (mtxrun  is the ConTeXt TDS Runner Tool) command from a terminal window it has has a large number of options for finding the fonts installed, and for querying their characteristics (see: Fonts out of ConTeXt (Hans Hagen, pg 52 and ff))

Em

On 2023-04-25 08:50, Werner Schmidt via ntg-context wrote:

Hi conTeXt folks,

may I ask again. How could I debug the font typesetting of PDF files with conTeXt?

Any help is highly appreciated.

Best Werner

On April 21, 2023 1:29:18 PM UTC, Werner Schmidt via ntg-context <ntg-context@ntg.nl> wrote:

Hi all,

I'd like to use the commercial Adobe Kepler typeface (Kepler Std - version 2.020) in conTeXt (v2023-04-15) as text (serif) font. Although the font files are loaded correctly (see log below), the generated PDF is unreadable (see attached image).

Notes:
- Only serif font (keplerstd-light.otf) is not working. It's not embedded in the generated PDF.
- italics and bold fonts are embedded and are rendered well
- Can't provide font files because Kepler is a commercial typeface

Do you have any ideas how to debug this issue?

Thanks Werner

log file:
mkiv lua stats > loaded fonts: 10 files: fontawesome6freesolid900.otf, frutigernextpro-bold.otf, frutigernextpro-regular.otf, iosevka-term-ss09-light.ttf, keplerstd-light.otf, keplerstd-lightcapt.otf, keplerstd-lightit.otf, keplerstd-semibold.otf, latinmodern-math.otf, lmroman10-regular.otf
mkiv lua stats > font engine: otf 3.133, afm 1.513, tfm 1.000, 30 instances, 18 shared in backend, 3 common vectors, 15 common hashes, load time 0.449 seconds
Example:

This text can't be read in PDF.par
{it However, italics are working.}par
{bold Also Bold and bfem BoldItalics!}par
input{zapf}

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