# [Tex/LaTex] How to determine the true size of a font

fontspdftex

A colleague of mine is submitting a research proposal to one of the UK research councils, whose guidelines stipulate a minimum font-size of 10pt. My colleague, who is of course using LaTeX, uses the amsart document class with the 10pt option (which, in fact, I think it's the default). Looking at the .log file one sees that the 10pt version of the fonts are indeed being loaded.

However word has come back that the proposal falls foul of the research council's guidelines because the font-size in the PDF file that my colleague submitted is actually 9.6pt! Alas, no information has been given as to how this font-size was determined.

### Questions

1. When is 10pt not really 10pt?

2. And how can one determine the true font size of a LaTeX-generated PDF document?

This just in: it seems that the culprit was the default scaling of helvetica, which according to the PSNFSS2e documentation (PDF file) is smaller than 1.