[Tex/LaTex] letter class font size

Question

How can I increase the base font size to 14pt in standard letter class using xelatex for ease of reading for presbyopic people? which font has better visibility?

Answer 1

You can use the Scale option, but you need to reset the main font; instead of Latin Modern you can use whatever font you want.

\documentclass[12pt]{letter}
\usepackage{fontspec}
\defaultfontfeatures{Scale=1.2}
\setmainfont{Latin Modern Roman}
\linespread{1.2}

\usepackage{lipsum}

\begin{document}
\begin{letter}{R. E. Cipient\\
  Some Place\\
  Some Street}

\opening{Hi,}

this is a letter about getting big type.

\lipsum[1-2]

\closing{Best regards}

\end{letter}
\end{document}