# How to specify document font size less than 8pt?

I want to use the smallest readable font for cheatsheet, \documentclass[6pt]{extarticle} doesn't work

• Welcome to TeX SX! It should be possible with xelatex, but who can read a 6pt font? – Bernard Jun 6 '16 at 17:31
• @Bernard I have Magnifying glass. – Eli Jun 6 '16 at 17:34
• If you use magnifying glass, you don't want such a small size… – Bernard Jun 6 '16 at 17:37
• Your answer suggests a local change to the font size, and therefore points to the following duplicate: Switching to different font size(s) locally – Werner Jun 6 '16 at 17:40
• Another option is to use a normal font size on a large paper format. Then shrink to fit a smaller paper format when printing. – James Jun 6 '16 at 19:35

The key is to pick a font that supports arbitrary scaling, such as lmodern, and then use the \fontsize{}{}\selectfont approach to select it. The revised font size will stay active until subsequently changed.

As to default size at startup, LaTeX only supports 10pt, 11pt, and 12pt, which is why the [6pt] option was ignored in the OP's approach.

\documentclass[12pt]{article}
\usepackage{lmodern}
\begin{document}
XYZxyz\par
\fontsize{11pt}{12pt}\selectfont XYZxyz\par
\fontsize{10pt}{11pt}\selectfont XYZxyz\par
\fontsize{9pt}{10pt}\selectfont XYZxyz\par
\fontsize{8pt}{9pt}\selectfont XYZxyz\par
\fontsize{7pt}{8pt}\selectfont XYZxyz\par
\fontsize{6pt}{7pt}\selectfont XYZxyz\par
\fontsize{5pt}{6pt}\selectfont XYZxyz\par
\fontsize{4pt}{5pt}\selectfont XYZxyz\par
\fontsize{3pt}{4pt}\selectfont XYZxyz\par
\fontsize{2pt}{3pt}\selectfont XYZxyz\par
\fontsize{1pt}{2pt}\selectfont XYZxyz
\end{document}

Eliminating the use of lmodern, one will find that the fontsize cannot be reduced below 5pt, since the default computer-modern font is not arbitrarily scalable.

p.s. With lmodern selected, one should just as well add \usepackage[T1]{fontenc} to the preamble, to take advantage of the extra glyph set.

Oh, sorry, I found the solution.

\begin{document} \tiny