Question about papersize A4 at 81%

Question

I'm going to print my thesis at the size of 81% A4 which is a beautiful paper format and pretty common with scientific publications. I'm wondering what's better:

• Either creating an document with a4paper option and scale it down at the printer? (Will I lose quality?)
• Or creating a document with some option that pre-defines 81% of A4? (Is there any option yet? Or will I have to define my own papersize?)

I'm currently using the documentclass report:

\documentclass[12pt,a4paper,twoside,openright]{report}

Answer 1

I'd go with the second option: if you have images they will lose quality when reduced by the printer.

If you have a printer with that paper size (but I bet you haven't) then

\documentclass[11pt,twoside,openright]{report}

\usepackage[paperwidth=170.1mm,paperheight=240.57mm,
            heightrounded]{geometry}
% \geometry{<other possible options>}

should do.

If instead you have to crop from A4paper, then

\documentclass[11pt,twoside,openright]{report}

\usepackage[a4paper,
  layoutwidth=170.1mm,layoutheight=240.57mm,
  layouthoffset=19.95mm,
  heightrounded,
  showcrop]{geometry}
% \geometry{<other possible options>}

In my opinion 12pt is too much for such a format. You get 33 lines of text; while with 11pt you get 35.

Answer 2

My guess is that the 81% requirement and the 12pt font size is specified in order to have the document reduced at the printer (this will scale to approximately 9.75pt font-size). You can have a look as to how the document will look by scaling it down yourself as per the MWE below:

\documentclass[twoside,a4paper]{report}
\usepackage{pgfpages}
\usepackage{graphicx}
\usepackage{lipsum}
\begin{document}
\pgfpagesuselayout{resize to}[physical paper width=0.81\paperwidth,
                physical paper height=0.81\paperheight]
\lipsum[1-15]
\end{document}

Probably the best advice you can get is to talk to your Printers and get their suggestions. If you do let us know what they said.