How can I make this type of section heading? (Section font is Montserrat)

Question

I want to have this type of section heading for my book.... Any suggestions how it can be achieved....

Answer 1

If you are using a KOMA-Script class, you can redefine \sectionlinesformat to add the rule and use \addtokomafont to change the color. To remove the chapter counter from the section number, you can use \counterwithout and \counterwithin* (if the section counter should still depend on the chapter counter).

\documentclass{scrbook}
\usepackage{montserrat}
\usepackage[svgnames]{xcolor}
\counterwithout{section}{chapter}
\counterwithin*{section}{chapter}
\makeatletter
\renewcommand*{\sectionlinesformat}[4]{%
  @hangfrom{\hskip #2#3}{#4}% Original code from scrbook.cls
  \Ifstr{#1}{section}{% For sections only
    \par\nobreak
    \rule[1ex]{\textwidth}{1pt}%
  }%
}
\makeatother
\addtokomafont{section}{\color{DodgerBlue}\nobreak}
\usepackage{blindtext}
\begin{document}
\chapter{Test}
\section{First section}
\blindtext
\section{Second section}
\blindtext
\section{Third section}
\blindtext
\section{Fourth section}
\blindtext
\section{Photodiode}
\blindtext
\end{document}

If you additionally want to change the space between the section number and the title text, you can redefine \sectionmarkformat. The original definition (from the KOMA-Script manual, Section 3.16) is:

\newcommand*{\sectionformat}{\thesection\autodot\enskip}

To, e.g., increase the space from half a quad to a full quad you could use

\renewcommand*{\sectionformat}{\thesection\autodot\quad}

Alternatively you can use every horizontal space you want, e.g., \qquad, \hspace{2em}, \hspace{1in}. To start the title text always at the same place, you can use a \makebox, e.g.,

\renewcommand*{\sectionformat}{\makebox[2in][l]{\thesection\autodot\hfill}}

You can even move the number into the left margin, as explained in an example in the KOMA-Script manual.

If you are not using a KOMA-Script class see the manual of the used class for information about similar features. If the class does not provide features to configure the section headings, you may use a package like titlesec. However, I'm almost always using KOMA-Script classes, so I cannot tell you, how the configuration has to be done in this case.