# How to make font sizes scale with paper size

I'm trying to create a poster using tcolorbox which has worked great but I noticed that I have done everything on a4paper paper size. When I change it to something like a1paper all the fonts are way too small. Specifying a font size like \documentclass[30pt]{article} doesn't seem to have an effect. What's the correct way to scale the fonts size for different paper sizes? I think beamerposter provides a scale argument for this purpose but I don't want to use beamer for this if I don't have to.

• the simplest way, if it is all done at A4 is simply to print the A4 PDF file on A1, the aspect ratios are identical so your print driver can simply scale the output, Jan 2, 2020 at 14:42
• You can also easily create an A1 version by including the A4 version as a scaled graphic into a document using A1, that way you get a A1 PDF that is just the scaled version (since some printing services require one to provide PDFs in the correct size). Jan 2, 2020 at 15:21
• A bit of googling and I came across this to do the rescaling and it seems to work great: pdfjam --a1paper --landscape --outfile poster_a1.pdf poster.pdf Jan 2, 2020 at 15:45

## 2 Answers

Option fontsize in tcbposter will scale all fonts to the desired size.

Design for Din A4 and then scale up to Din A3. Change 430pt to your \textwidth in Din A4 and use a font that is good to scale, for example lmodern

\documentclass{article}
\usepackage[a3paper]{geometry}
\usepackage{lmodern}
\usepackage[most]{tcolorbox}
\usepackage{graphicx}
\begin{document}

\noindent%
\resizebox{\textwidth}{!}{%
\begin{minipage}{430pt}%
\begin{tcolorbox}[title={Foo}]
test
\end{tcolorbox}%
\end{minipage}%
}

\end{document}