How do I get a light math font?

Question

Here is my problem. I'm using the font sourceserifpro, with the "extralight" mode, and I'm getting this as a result:

As you may see, the math formulas appear a bit darker than the rest of the text, as if they were bold. Whence my question: is it possible to make the math formulas lighter or brighter ?

(A very naive idea would be to make these formulas grey instead of black — automatically. A naive idea would be to make them less "opaque", i.e. more "transparent" — again automatically). But I don't know any way of "thinning" those math symbols.

I hope that my question is clear and that I will get some... enlightning answers!

Here is the MWE:

\documentclass{report}
\usepackage[default,extralight]{sourceserifpro}

\begin{document}
Given elements $a_1, ..., a_n \in k$, we denote by $\mathrm{diag}(a_1, ..., a_n) \in M_n(k)$
the diagonal matrix whose $(i,j)$-th entry 
is $a_i \delta_{i,j}$ for any $1 \leq i,j \leq n$.
\end{document}

You cannot make the font thinner. The outlines are fixed. You could grab the Metafont sources of Computer Modern and produce your own fonts with lighter weight, but this is probably an effort you don't want to take. — Henri Menke, Jan 04 '18 at 22:51
@HenriMenke : in that case, what about the (very) naive ideas I proposed in my question? — Watson, Jan 04 '18 at 23:08
this question Is it possible to use custom font as math font?, which appeared earlier today, may be useful for letters and digits, but i'm at a loss what to do about symbols. maybe someone else has some good ideas. — barbara beeton, Jan 04 '18 at 23:12
@JohnKormylo : yes, but is it possible to have "lightgray" activated automatically for all the math formulas in the document (instead of adding the command manually at each formula...)? — Watson, Jan 05 '18 at 18:49
Not unless you willing to replace $...$ with a macro; e.g. \math{...}. OTOH, I really don't know how $ is implemented. — John Kormylo, Jan 05 '18 at 19:45

score 3 · Accepted Answer · answered Jan 25 '18 at 23:00

You can color the math font automatically if you are willing to use unicode-math with LuaLaTeX (better don't use XeLaTeX).

\documentclass{report}
\usepackage{xcolor}
\usepackage{unicode-math} % loads fontspec
\setmainfont{Source Serif Pro Extra Light}
\setmathfont[Color=lightgray]{Latin Modern Math}
\setmathrm[Color=lightgray]{Latin Modern Math}

\begin{document}
Given elements $a_1, ..., a_n \in k$, we denote by $\mathrm{diag}(a_1, ..., a_n) \in M_n(k)$
the diagonal matrix whose $(i,j)$-th entry 
is $a_i \delta_{i,j}$ for any $1 \leq i,j \leq n$.
\end{document}

How do I get a light math font?

1 Answers1