# Changing the font size of subscripts for a certain text font size

I want to make my subscripts smaller, but only if the text font is in \scriptsize. Is there a way to do this? All proposed solutions to make subscripts smaller that I could find so far didn't change anything at all unfortunately.

Here is my current preamble as well as some sample equations:

\documentclass[12pt]{article}

\usepackage[a4paper, top = 0.8cm, left = 1cm, right = 1cm, bottom = 0.8cm]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{ulem}
\usepackage{graphicx}
\usepackage{multicol}
\usepackage{multirow}
\usepackage{array}
\usepackage{xcolor}
\usepackage{tabularx}

\newcolumntype{C}[1]{>{\centering\arraybackslash}m{#1}}
\newcolumntype{L}[1]{>{\arraybackslash}m{#1}}

\renewcommand{\tabularxcolumn}[1]{m{#1}}
\newcolumntype{Y}{>{\raggedright\arraybackslash}X}

\newcommand\Bstrut{\rule[-1ex]{0pt}{0pt}}
\newcommand{\specialcell}[2][c]{%
\begin{tabular}[#1]{@{}c@{}}#2\end{tabular}}

\begin{document}
{\scriptsize
\begin{align*}
F_S &= \text{Schraubenkraft}\\
F_P &= \text{Plattenkraft}\\
F_V &= \text{Vorspannkraft}\\
f_S &= \text{Verkürzung der Schraube}\\
f_P &= \text{Verkürzung der Platten}\\
\end{align*}}
\end{document}


It currently looks like this:

Thanks!

\RequirePackage{fix-cm}%scalable cm
\documentclass[12pt]{article}

\usepackage[a4paper, top = 0.8cm, left = 1cm, right = 1cm, bottom = 0.8cm]{geometry}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{ulem}
\usepackage{graphicx}
\usepackage{multicol}
\usepackage{multirow}
\usepackage{array}
\usepackage{xcolor}
\usepackage{tabularx}

\newcolumntype{C}[1]{>{\centering\arraybackslash}m{#1}}
\newcolumntype{L}[1]{>{\arraybackslash}m{#1}}

\renewcommand{\tabularxcolumn}[1]{m{#1}}
\newcolumntype{Y}{>{\raggedright\arraybackslash}X}

\newcommand\Bstrut{\rule[-1ex]{0pt}{0pt}}
\newcommand{\specialcell}[2][c]{%
\begin{tabular}[#1]{@{}c@{}}#2\end{tabular}}

\DeclareMathSizes
{8}% Specification of math fonts for this size of surrounding text
{8}% size of \displaystyle and \textstyle
{2}% size of \scriptstyle
{1}% size of \scriptscriptstyle

\begin{document}
{\scriptsize
\begin{align*}
F_S &= \text{Schraubenkraft}\\
F_P &= \text{Plattenkraft}\\
F_V &= \text{Vorspannkraft}\\
f_S &= \text{Verkürzung der Schraube}\\
f_P &= \text{Verkürzung der Platten}\\
\end{align*}}
\end{document}

• Thank you, the \Requirepackage{fix-cm} did the trick! May I ask what the two latter parameters do exactly? I know that I can change the size by changing both of them, but what does each one of them do? – Skydiver May 11 '17 at 18:58
• @Skydiver added commented version – David Carlisle May 11 '17 at 19:01
• What would be the values to change \footnotesize as well? – Skydiver May 11 '17 at 19:55
• do what I did use \makeatletter\footnotesize\show\f@size and see what size it says:-) – David Carlisle May 11 '17 at 19:58
• @Skydiver (but size12.clo has \newcommand\footnotesize{\@setfontsize\footnotesize\@xpt\@xiipt so footnotesize is 10pt so you want the first two arguments to be 10 – David Carlisle May 11 '17 at 20:00