More precise font size

You can change the Base Font Size on the Layout page, but it only accepts down to the tenth of a point. Sometimes just tweaking it a little bit one way or another makes a significant improvement in the overall layout of a book, especially for longer books.

I believe that this Base Font Size is just converted to the corresponding \FontSizeUnit, where 1.000pt corresponds to 12 pt. So if you want more precise font size, you can add these lines to your ptxprint-mods.tex file (the first two of which are comments):

% For more precise font size, divide into 12
% E.g. 10.85 / 12 -> 0.904pt
\FontSizeUnit=0.904pt

Then do the calculation to get whatever precision font size you want. This will just override whatever \FontSizeUnit gets defined from the Layout page.

If you want ptxprint to allow editing of the font size down to 1/100th or even 1/1000th of a point then raise an issue on github to ask for it. I don’t think we would want go down to 1/10000th of point, but TeX is accurate to 1/65536 of a point, although then rounding of calculations starts to mess with you as you enter the quantom foam!

'Twas easier to fix than deal with issues. The main font size is good to 1/100th of a point in 1.4.3 and following.