How to have a newline after a manual break in LaTex Article Title?

Question

I want to have a general approach causing a newline after a break in the title field without using bugs in 3rd party packages. I know the thread How do I manually break a line in a custom title of Maine University package? which is only about one university package. Approaches discussed in the thread do not work here: \protect\\, \parbox and other attempts: \vspace{}, ... Code and its output in Fig. 1

\documentclass{article}
\usepackage[utf8]{inputenc}

\begin{document}
\title{Using ionizing potatoes and effects on hippocambuctemia and
horshoes in happiem mode locations\\ 
\large RESEARCH PAPER}

\maketitle
\end{document}

Fig. 1 Output

Expected output: newline between the normal text and the capitalised text
Line break start: just before \large, or any suitable punctuation mark

Answer 1

You can do with

\documentclass{article}

\begin{document}

\title{Using ionizing potatoes and effects on hippocambuctemia and
  horshoes in happiem mode locations\\
  {\large RESEARCH PAPER}}

\maketitle

\end{document}

Optionally, use \\[2ex] (or whatever spacing you prefer).

The spacing you're seeing with your code can be explained, of course.

The title is set in \LARGE size, which means, for article at 10pt, font size 17pt (actually 17.28pt) on a 22pt baseline skip; on the other hand, \large has 12pt size on 14pt.

The \\ break ends a paragraph, because the title is processed under the scope of \centering, which is so typeset on a 22pt baseline skip; the second part again makes a paragraph (there is an implicit \par at the end) typeset on a 14pt baseline skip.

With braces around {\large RESEARCH PAPER}, the effect of \large will end before the implicit \par is executed, so the baselineskip will again be 22pt.

However, a strategy such as

\documentclass{article}

\begin{document}

\title{Using ionizing potatoes and effects on hippocambuctemia and
  horshoes in happiem mode locations\\[2ex]
  \large RESEARCH PAPER\\WHATEVER}

\maketitle

\end{document}

is necessary if you need two lines in \large and them not to be excessively spaced.

Take your pick.