Define Size of Certain Characters in the Preamble

Question

For card suit symbols I want to use the ones in MnSymbol. How can I define their default size one level higher? (Not sure if I put the question correctly: Basically, if text size is normal, I want them large, etc.)

Answer 1

Here I saved \spadesuit as \svspadesuit and then redefined the original as a 20% enlargement. I show both for comparison, in several text sizes.

While the original, \svspadesuit, must be used in math mode, the redefined \spadesuit can be used in math or text mode. It will not, as presently redefined, capture different mathstyles, like subscripting, etc. If that is a requirement, perhaps the OP will let me know.

\documentclass{article}
\usepackage{MnSymbol,graphicx}
\let\svspadesuit\spadesuit
\def\spadesuit{\scalebox{1.2}{$\svspadesuit$}}
\begin{document}
$\svspadesuit\spadesuit$
\Large$\svspadesuit\spadesuit$
\Huge$\svspadesuit\spadesuit$
\end{document}

Answer 2

I wouldn't load MnSymbol just for the card suit symbols, because this also changes all the math symbols.

\documentclass{article}

\DeclareFontFamily{U}{MnSymbolCards}{}

\DeclareFontShape{U}{MnSymbolCards}{m}{n}{
    <-6>  s*[1.2] MnSymbolC5
   <6-7>  s*[1.2] MnSymbolC6
   <7-8>  s*[1.2] MnSymbolC7
   <8-9>  s*[1.2] MnSymbolC8
   <9-10> s*[1.2] MnSymbolC9
  <10-12> s*[1.2] MnSymbolC10
  <12->   s*[1.2] MnSymbolC12}{}

\newcommand{\mndiamond}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A2}}}
\newcommand{\mnheart}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A3}}}
\newcommand{\mnspade}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A4}}}
\newcommand{\mnclub}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A5}}}

\begin{document}

x\mndiamond\mnheart\mnspade\mnclub y

\end{document}

Here is a comparison, just to show that the symbols are indeed larger:

\documentclass{article}

\usepackage{MnSymbol} % just for comparison

\DeclareFontFamily{U}{MnSymbolCards}{}

\DeclareFontShape{U}{MnSymbolCards}{m}{n}{
    <-6>  s*[1.2] MnSymbolC5
   <6-7>  s*[1.2] MnSymbolC6
   <7-8>  s*[1.2] MnSymbolC7
   <8-9>  s*[1.2] MnSymbolC8
   <9-10> s*[1.2] MnSymbolC9
  <10-12> s*[1.2] MnSymbolC10
  <12->   s*[1.2] MnSymbolC12}{}

\newcommand{\mndiamond}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A2}}}
\newcommand{\mnheart}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A3}}}
\newcommand{\mnspade}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A4}}}
\newcommand{\mnclub}{{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A5}}}

\begin{document}

x$\diamondsuit\heartsuit\spadesuit\clubsuit$y

x\mndiamond\mnheart\mnspade\mnclub y

\end{document}

Here's the version for using the symbol also in math mode:

\documentclass{article}
\usepackage{amsmath}

\DeclareFontFamily{U}{MnSymbolCards}{}
\DeclareFontShape{U}{MnSymbolCards}{m}{n}{
    <-6>  s*[1.2] MnSymbolC5
   <6-7>  s*[1.2] MnSymbolC6
   <7-8>  s*[1.2] MnSymbolC7
   <8-9>  s*[1.2] MnSymbolC8
   <9-10> s*[1.2] MnSymbolC9
  <10-12> s*[1.2] MnSymbolC10
  <12->   s*[1.2] MnSymbolC12}{}

\newcommand{\mndiamond}{\text{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A2}}}
\newcommand{\mnheart}{\text{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A3}}}
\newcommand{\mnspade}{\text{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A4}}}
\newcommand{\mnclub}{\text{\usefont{U}{MnSymbolCards}{m}{n}\symbol{"A5}}}

\begin{document}

$\mndiamond+\mnheart=\mnspade+\mnclub$

$A_{\mndiamond}$

\end{document}