The fontsize commands of LaTeX, e.g. \small
, \large
, etc. work in relation to the global fontsize of the document. Hence, they change if the font size of the document changes. For a detailed overview see
What point (pt) font size are \Large etc.?
In concrete they are used like a switch. For example
\documentclass{article}
\usepackage{lipsum}
\begin{document}
%Some normal sized text, no changes
\lipsum[1]
%smaller text from here
\small
\lipsum[2]
%again normal sized
\normalsize
\lipsum[3]
\end{document}
You can of course limit the effect of those macros to a group, i.e. {\small This text is small\par}
. In this case text that follows the group won't be affected. (Note the \par
concluding the group to apply the correct line spacing.)
Now, you can change the font size of the document globally by declaring the 10pt
, 11pt
or 12pt
option while calling the documentclass as:
\documentclass[11pt]{article}
Regarding your example I used the titlesec
package to patch the sectional headings. The customization of the title and the abstract - note that I added a \keywords
macro - is hand-crafted. A complete code could be:
\documentclass[11pt]{article}
\usepackage{lipsum}
\usepackage[T1]{fontenc}
\renewcommand\rmdefault{ptm}
\usepackage{textcase,url,titlesec}
\titleformat{\section}{\relax}
{\large\BoldAllcaps{\thesection}}{1em}{\large\BoldAllcaps}
\newcommand{\BoldAllcaps}[1]{\MakeTextUppercase{\scshape\bfseries #1}}
\makeatletter
\renewcommand\@maketitle{%
\newpage
\null
\vskip 2em%
\begin{center}%
\let \footnote \thanks
{\Large\bfseries \@title \par}%
\vskip 1.5em%
{\large
\lineskip .5em%
\begin{tabular}[t]{c}%
\@author
\end{tabular}\par}%
\vskip 1em%
{\small \@date}%
\end{center}%
\par
\vskip 1.5em}%
\renewenvironment{abstract}{\section*{\abstractname}}{\relax}
\newcommand{\keywords}[1]{\par\vspace{.5em}\noindent{\large\bfseries \keywordsname:} #1\par}
\def\keywordsname{Keywords}
\makeatletter
\title{Title of paper}
\author{Author}
\date{Affiliation, \url{e@ma.il}}
\begin{document}
\maketitle
\begin{abstract}
\lipsum[1]
\keywords{blah, blah}
\end{abstract}
\section*{Introduction}
\lipsum[2]
\end{document}

article
knows options10pt
,11pt
, and12pt
. This changes all elements controlled by a font-size switch (headers, footnote ...). You can find the actual pointsize insize10.clo
(substitute the 0 with 1 or 2 for 11pt or 12pt respectively).\fontsize{newsize}{baselineskipfaktor}\selectfont
could be used