# Changing interline

I do not know why, but my code provides a text with different values of interline. To be more clear, let me show my code:

\documentclass[12pt,a4paper, english]{article}
\usepackage{graphicx,amssymb}
\textwidth=15cm \hoffset=-1.2cm
\textheight=25cm \voffset=-2cm

\pagestyle{empty}

\date{\today}
\def\keywords#1{\begin{center}{\bf Keywords}\\{#1}\end{center}}

\begin{document}

\title{Title}

\author{\textit{Author} \\
University\\\\
}

\maketitle

\thispagestyle{empty}

\keywords{keywords}
%
%
\vspace{0.7cm}
{\Large{\textbf{Introduction}}}\\\\
%
Text 1
$$u^{k+1}$$
Text 2
%
\begin{footnotesize}
\begin{thebibliography}{9}
%
\bibitem{blabla}
Blabla.
\end{thebibliography}
\end{footnotesize}
\end{document}


The result is shown below:

As you can see the text below the formula has an interline smaller than the previous. If I remove \begin{footnotesize} and \end{footnotesize} (bibliography), I get what I want (same interline for both text). Any suggestion to have same interline and font size smaller for bibliography? Thank you!

• Add a blank line before \begin{footnotesize}. Are you sure you want {\Large{\textbf{Introduction}}}\\\\\\ instead of \section*{Introduction}? – egreg Feb 11 '18 at 16:29
• really so easy? Thanks so much!! – Mik Feb 11 '18 at 16:30
• Actually, what you propose is better. Thank you! – Mik Feb 11 '18 at 16:32
• \Large does not have an argument... – user31729 Feb 11 '18 at 16:39

Whenever you see \\\\, you know that something is wrong with the document. Always.

Also, you seem to be worried about blank lines: don't. They're good!

The problem you have is indeed the absence of a blank line before \begin{footnotesize}, so the final paragraph is broken into lines for typesetting when \footnotesize is already in force.

Here's an edited version of your document (using \hoffset and \voffset is to be avoided).

\documentclass[12pt,a4paper]{article}
\usepackage{amsmath,amssymb}
\usepackage[
textwidth=15cm,
textheight=25cm,
heightrounded,
]{geometry}

\usepackage[nopar]{lipsum} % for mock text

\newcommand\keywords[1]{\begin{center}\textbf{Keywords}\\#1\end{center}}

\pagestyle{empty}

\begin{document}

\title{Title}
\author{%
\textit{Author}\\
University
}
\date{\today}
\maketitle

\thispagestyle{empty}

\keywords{keywords}

\section*{Introduction}

\lipsum[1]
$$u^{k+1}$$
\lipsum[2]

\begin{footnotesize}\renewcommand{\Large}{\normalsize}
\begin{thebibliography}{9}

\bibitem{blabla}
Blabla.

\end{thebibliography}
\end{footnotesize}

\end{document}


The lipsum package is just for filling with nonsense text. I also reduced the size of the heading for the references.

• Your answer was very useful for me. Thank you so much! – Mik Feb 11 '18 at 17:03