How do I scale mathbbol symbols?

Question

I have need of blackboard bold Greek symbols so am using the mathbbol package. I would prefer to have the symbols at 1.1 design size, say. How do I arrange to scale all the bbol symbols by this factor?

Answer 1

This is what you get from the standard:

\documentclass{article}

\usepackage{mathbbol}

\begin{document}

X$\mathbb{\Gamma}$X

\end{document}

We can add a declaration for the font family where the fonts are scaled by 1.1

\documentclass{article}

\DeclareFontFamily{U}{bbold}{}
\DeclareFontShape{U}{bbold}{m}{n}
 {  <-5.5> s*[1.1] bbold5
    <5.5-6.5> s*[1.1] bbold6
    <6.5-7.5> s*[1.1] bbold7
    <7.5-8.5> s*[1.1] bbold8
    <8.5-9.5> s*[1.1] bbold9
    <9.5-11.5> s*[1.1] bbold10
    <11.5-16> s*[1.1] bbold12
    <16-> s*[1.1] bbold17
 }{}

\usepackage{mathbbol}

\begin{document}

X$\mathbb{\Gamma}$X

\end{document}

The font declaration results from the standard ubbold.fd file, taking into account that the font is now available in scalable format.

Answer 2

Because the question is not LaTeX specific, here is plain TeX solution using OPmac:

\input opmac

\regtfm msbm 0 bbold5 5.5 bbold6 6.5 bbold7 7.5 bbold8 8.5 bbold9 
         9.5 bbold10 11.1 bbold12 15 bbold17 * % using bbchar from bbold*.tfm

\def\corrmsizes{\ptmunit=1\ptunit\relax    % no scale by default
     \ifnum\tmp=5 \ptmunit=1.1\ptmunit \fi % scaling the family 5
}
\normalmath

X$\bbchar\Gamma$X

\bye