# Force \fontdimen 6 for a specific font to silent a microtype warning

I am using the packages fdsymbol together with the microtype package and there are many warnings a compile time stating the following:

Package microtype Warning: Font U/FdSymbolF/m/n/14.4' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Is there a way to patch the fdsymbol package (i.e. to set \fontdimen 6 to some value) to fix this warning ?

EDIT

As asked by egreg, here is an example (which somehow made me discover what was causing the problem... but not solving it).

\documentclass{article}

\usepackage{fdsymbol}
\usepackage[tracking=all]{microtype}

\begin{document}
\ensuremath{\varheartsuit}
\end{document}

It seems to be caused by the tracking.

Here is the full warning log for my full document.

Package microtype Warning: Font U/FdSymbolE/m/n/40' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolE/m/n/27.99988' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolE/m/n/20' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolB/m/n/40' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolB/m/n/27.99988' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolB/m/n/20' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolC/m/n/40' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolC/m/n/27.99988' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolC/m/n/20' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolD/m/n/40' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolD/m/n/27.99988' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolD/m/n/20' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolF/m/n/40' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolF/m/n/27.99988' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.

Package microtype Warning: Font U/FdSymbolF/m/n/20' does not specify its
(microtype)                \fontdimen 6 (width of an em')! Therefore,
(microtype)                tracking will not work with this font.
• Can you please make a small example that produces the warning? – egreg Jun 11 at 16:53
• just asking: do you really want to add tracking to all fonts? – Robert Jun 11 at 17:37
• @Robert Obviously not... I realized it now. :-/ – perror Jun 11 at 17:40
• Well, I was too optimistic... tracking=alltext did remove some warnings but not all, so the question is still requiring an answer. – perror Jun 11 at 18:52
• Your code produces no warning with tracking=alltext – egreg Jun 11 at 22:31

As egreg mentionned it in the comments, setting the microtype package to tracking=alltext is enough to remove all the warnings from the basic example.

But, my code is producing a lot more warnings and I did not yet to reproduce it in a small example... In fact, I am using only a few symbols from the fdsymbol package, so I found a workaround as follow :

\DeclareFontFamily{U}{FdSymbolA}{}
\DeclareFontShape{U}{FdSymbolA}{m}{n}{<->FdSymbolA-Book}{}
\DeclareSymbolFont{extrasymbols}{U}{FdSymbolA}{m}{n}
\DeclareMathSymbol{\varheartsuit}{\mathord}{extrasymbols}{184}
\DeclareMathSymbol{\medblacksquare}{\mathord}{extrasymbols}{118}
\DeclareMathSymbol{\medblackbullet}{\mathord}{extrasymbols}{99}

But, it looks like the fdsymbols are used in many more places thant I expected first.

So, I wouldn't say that this answer is the right one. It is just a workaround and I need to discover what is the root of the problem.

• again, are you really sure you want to add tracking to all text fonts? This would be very unusual. Can you say why you want that? – Robert Jun 12 at 18:09
• Not really, but I would like to know how to specify what fonts are taken into consideration and what fonts to exclude. I tried to add \SetExtraSpacing{font=TS1/FdSymbol*/*/*/*}{} with no effect... – perror Jun 13 at 7:20
• see section 4 of the microtype manual: Selecting fonts for micro-typography. As @egreg said, with alltext the FdSymbol font will not be tracked, so you are doing something else than what you show us (maybe there's math inside a \textls command?) – Robert Jun 14 at 14:04
• @Robert Yes, that was exactly the problem! I've got some text inside \textls{} and this is what produced these warnings... Thanks a lot, I do not think I would have find it out alone! – perror Jun 14 at 18:18