# How to make math text lighter

I saw here how to make body text lighter. The command is

\font\tenrm = cmr17 at 10pt \tenrm


How can I do the same thing to math text? Note: I want to use Computer Modern, not kpfonts, etc. Here is a minimal working example:

\documentclass[]{amsart}
\begin{document}

\font\tenrm = cmr17 at 10pt \tenrm

\noindent
This experiment tested the validity of Kirchoff's current and voltage laws:
$(i) \sum \limits_{\textrm{junction}} \! \! \! I = 0$
$(ii) \sum \limits_{\textrm{closed loop}} \! \! \! \! \! \! \Delta V = 0$
using a two-loop circuit and appropriate measuring equipment. It was determined
that Kirchoff's circuit laws closely agree with observation (see Table 1).

\end{document}


When I add the command to make the body text lighter, the math font doesn't change. I would like it to be as light as the body text. I want the bold to be lighter too. This would make it look like the newer Springer books, which have very nice formatting. Thanks.

• You don't say what tex format you are using, or give an example document. The code that you show is plain TeX, do you want a plain tex solution? (your other questions are all using latex, but you shouldn't use \font in latex) 999 times out of 1000 when people comment on the weight of the cm series they complain that it is so light which makes it difficult to combine with any other font:-) – David Carlisle Mar 11 '14 at 0:06
• Doesn't Springer use Times New Roman? That's what they use for journals, and I just checked that it's what's in their template for books, too. \usepackage{mathptmx} will switch your fonts to Times. – Nick Matteo Mar 11 '14 at 1:09
• I think it's actually just the high-resolution printing they use. And I guess it depends on the book. The ones I get use Computer Modern. – Randy Randerson Mar 11 '14 at 2:02

You can use \DeclareFontShape to do this, and this is what you should also be doing for the text changing. However, it is a big task you need to treat each font loaded in each variant. See files such as amsfonts.sty, source2e.pdf and files such as omlcmr.fd referenced therein to see relevant information. Below is the sample of using your command and on redefinition for one of the math fonts:

Before without font changing:

After the two font changes:

\documentclass{amsart}

\DeclareFontShape{OMX}{cmex}{m}{n}{%
<-7.5>cmex11%
<7.5-8.5>cmex12%
<8.5-9.5>cmex14%
<9.5->cmex17%
}{}%

\begin{document}

\font\tenrm = cmr17 at 10pt \tenrm

\noindent
This experiment tested the validity of Kirchoff's current and voltage laws:
$(i) \sum \limits_{\textrm{junction}} \mkern-12mu I = 0$
$(ii) \sum \limits_{\textrm{closed loop}} \mkern-18mu V = 0$
using a two-loop circuit and appropriate measuring equipment. It was determined
that Kirchoff's circuit laws closely agree with observation (see Table 1).

\end{document}