Crop A4 thesis to B5

Question

I have a thesis with the following A4 layout (scrbook, 10pt, twoside, calculated DIV):

For even sides, the \oddsidemargin changes to \evensidemargin = 98pt

I'd like to keep all sizes etc. the same, just crop the margins down to B5. How to do this best? With best I mean simple and satisfactory from a typographical point of view. I had a look at Adding crop marks to a4 document to crop it to book without changing the layout?, with the differences being to my case that:

• I do not use the geometry package (yet?).
• I'm not sure how to best determine the new margins.

Answer 1

Unfortunaly there is no MWE in the question. Using the following code (twoside is default for scrbook)

\documentclass[fontsize=10pt,DIV=calc]{scrbook}
\usepackage{layout}
\begin{document}
\layout
\end{document}

I get the following sizes:

Then I can change the paper format to B5 still using the same height and width of the text body:

\KOMAoptions{paper=B5,areasetadvanced}
\areaset[current]{\textwidth}{\textheight}

Package crop can be used for a frame or crop marks.

\usepackage[a4,center,
  frame,% either from
  %cam% or crop marks
]{crop}

MWE:

\documentclass[fontsize=10pt,DIV=calc]{scrbook}
\KOMAoptions{paper=B5,areasetadvanced}
\areaset[current]{\textwidth}{\textheight}
\usepackage[a4,center,
  frame,% either from
  %cam% or crop marks
]{crop}
\usepackage{layout}
\begin{document}
\layout
\end{document}

Result with option frame for package crop:

or with option cam for package `crop:

Note, that not only the edges are cropped, the margin notes are also narrower.

Answer 2

What is the printing process for the thesis? If you have your own printer it probably takes A4 paper (B5 paper is not commonly available in the regular High Street shops). Will the final thesis be printed on B5 paper or on A4 then trimmed down to B5?

I don't use Koma but the memoir class has a b5paper option --- perhaps Koma has something similar. Anyway, what I would do is to create a short (3 page?) document for B5 paper and see how it looks, adjusting the margins to give a good appearance. Then you will have an idea of how to set the margins on A4 paper so that when it is trimmed to B5 it will look good.

memoir has its methods for setting the page layout; perhaps Koma does as well, otherwise use the geometry package.