# kpfonts and Computer modern

there are typographical contraindications to use kpfonts for the text and standard Computer modern for the Math mode?

\documentclass[a4paper]{memoir}

\usepackage[nomath,fulloldstylenums,fulloldstyle]{kpfonts}

\begin{document}
ciaostffi

$\int a+b=c^2\sum\partial\nabla\psi\ell$

\end{document}

-
It's always better not to mix fonts in the text body. If you type a variable name or inline formula, it will definitely look awkward. May I ask why you want two different fonts? –  Timothée Poisot Aug 10 '12 at 14:24

use

\documentclass[a4paper]{memoir}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage[nomath,fulloldstylenums,fulloldstyle]{kpfonts}
...


then you'll get:

voss@shania:~/Test> pdffonts test.pdf
name                                 type              emb sub uni object ID
------------------------------------ ----------------- --- --- --- ---------
JONXPB+Kp-Companion-Regular          Type 1            yes yes no       4  0
SDCAJC+Kp-Regular                    Type 1            yes yes no       5  0
YPARFD+Kp-Expert-Regular             Type 1            yes yes no       6  0
WHFDFR+LMMathExtension10-Regular     Type 1            yes yes no       7  0
IPZDPD+LMMathItalic10-Regular        Type 1            yes yes no       8  0
NZUYHE+LMRoman10-Regular             Type 1            yes yes no       9  0
SDXHST+LMRoman7-Regular              Type 1            yes yes no      10  0
HXDVWF+LMMathSymbols10-Regular       Type 1            yes yes no      11  0

-

I'm not sure what exactly you mean by "typographical counter-indications".

It is certainly the case that the kpfonts text-mode and math-mode fonts are quite different from their Computer Modern and Latin Modern counterparts. The Kepler font, being derived from the famous Palatino font, is best classified as "oldstyle" or "Garalde". The Computer Modern fonts are, well, "modern" in style. Three of most readily apparent differences are:

• modern fonts tend to feature a higher ratio between the thickest and thinnest parts of each letter, leading to a higher "contrast" within letters
• the Computer/Latin Modern fonts are also noticeably less "dark" in overall appearance than are the Palatino/Kepler fonts when set on a page
• the x-heights of the two font families (when set at the same nominal size of, say, 10 points) also differ noticeably (kpfonts/Palatino featuring the larger x-heights)

Whether the presence of such differences amounts to a clear-cut counter-indication against mixing these two fonts in a single document, I will have to leave up to you to decide. It's often said that typographic "rules" are meant to be broken -- or at least bent -- at times. However, as with most rules, it's probably also true that the bending or breaking of typographic rules better be done deliberately and with a clear reason in mind.

-