Including tex file in an org file

Question

I have a tex file containing lots of standard settings such as packages to be included and various other options. How do I tell Org mode to use only the settings from that TeX file?

i.e. for all practical purposes, the org-document should only export to a tex file the part between \begin{document}...\end{document} whereas the other document settings such as what documentclass and packages to use are borrowed directly from the .tex file. By default Org creates the preamble like

\documentclass[11pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage{grffile}
\usepackage{amssymb}

..

which I don't want

Answer 1

You need to add your own preamble to org-latex-classes and you also can exclude the default packages from beeing loaded (see the description of that variable).

The following works for me. Put

(add-to-list 'org-latex-classes
         '("my-org-latex-class"
           "\\documentclass[option1,option2]{myclass}
     [NO-DEFAULT-PACKAGES]
     [PACKAGES]
     \\usepackage{mypackage1}
     \\usepackage{mypackage2}"))

somewhere to your org config. Then an org-file like

 #+TITLE: test
 #+AUTHOR: My name
 #+LaTeX_CLASS: my-org-latex-class

 * Introduction
   Intro text 

produces a tex-file without the default packages. If you are not using the package hyperref you also might want to set the variable org-latex-with-hyperref to nil.