[Tex/LaTex] Book geometry with margins and binding offset

geometry

The mwe given below illustrates my current settings in the book am working. Unfortunately I find it a bit cumbersome and outdated although it achieves what I want it to do. One of my objectives is to have both even and odd pages have the margin on the left side; this has been done. My issue is that I don't think the spacing are the same for both pages. For example, for page 2, the binding is on the right and on 3 it is on the left and showframe does not show the margin paragraph section.

What I want is that all lengths are accounted for and that both pages are technically the same. I feel like I am forcing the geometry to look like what I want.

enter image description here

\documentclass[11pt,twoside,openany]{book}
\usepackage[
    letterpaper,
    bindingoffset=0.2in,
    centering,
    marginparwidth=2in,
    textwidth=5.1in,
    marginparsep=2em,
    top=2.5cm,
    bottom=2cm,
    showframe
]{geometry} 
\evensidemargin 1.5in
\oddsidemargin 2in 

\usepackage{etoolbox}

\makeatletter
\patchcmd{\@mn@margintest}{\@tempswafalse}{\@tempswatrue}{}{}
\patchcmd{\@mn@margintest}{\@tempswafalse}{\@tempswatrue}{}{}
\reversemarginpar
\makeatother

\usepackage{lipsum}
\begin{document}
\lipsum[1-12]
\end{document}

Here is an example of what I would like to achieve and the link to the sample.

enter image description here

The image below gives an overview of the layout I am seeking to achieve.

enter image description here

Best Answer

The different values for \evensidemargin and \oddsidemargin seem questionable to me if you're trying to have a two-sided document have exactly the same off-centred layout.

I'm not sure what you mean by 'margin paragraph section', but if you mean you want the \marginpars to end up always on the left-hand side of both the recto and verso pages, then maybe the following works. (\marginpars can be frustrating to work with.)

\documentclass[11pt,twoside,openany]{book}
\usepackage[
    letterpaper,
    bindingoffset=0.2in,
    centering,
    marginparwidth=2in,
    textwidth=5.1in,
    marginparsep=2em,
    top=2.5cm,
    bottom=2cm,
    showframe
]{geometry}
\evensidemargin 1.5in
\oddsidemargin 1.5in

\usepackage{etoolbox}

\makeatletter
\patchcmd{\@mn@margintest}{\@tempswafalse}{\@tempswatrue}{}{}
\patchcmd{\@mn@margintest}{\@tempswafalse}{\@tempswatrue}{}{}
%\reversemarginpar
\makeatother

\usepackage{ifoddpage}
\newcommand\mmp[1]{%
  \checkoddpage
  \ifoddpage
   \reversemarginpar
   \marginpar[#1]{}
  \else
   \normalmarginpar
   \marginpar{#1}
  \fi
}

\usepackage{lipsum}
\begin{document}
\mmp{Odd, left-hand side}
\lipsum[1-6]
\mmp{Even, left-hand side}
\lipsum[7-12]
\mmp{Odd again, left-hand side}
\end{document}
Related Question