scrbook - twoside produces shorter, not longer, binding margins

Question

I use KOMA-Script and I want to print it two-sided. However, in the two-sided view margin for the open edge (right for odd pages) is wider than for the binding edge.

• -Is it the indented behavior?- (OK, I see it might be: Illogical twoside margins.)
• Is it possible to swap it? (I am printing my PhD thesis and the space for binding is non-negligible).

Example:

\documentclass[twoside,10pt]{scrbook}

\begin{document} 

\mainmatter

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

\newpage

Continued:

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

\end{document}

Result (the first page):

Answer 1

The behaviour is correct.

Please try the following MWE:

\documentclass[%
  twoside
 ,10pt
%,BCOR20mm      % Adds 20 mm for binding 
]{scrbook}

\usepackage{showframe}  % to show typing area, header, footer, margins
\usepackage{blindtext}  % To create a dummy document

\begin{document} 
\Blinddocument
\end{document}

Compile it first with the % in the class option line (line 4). The result shows you the resulting typing area. Now compile without the %. The result is that a binding correction is added. This place is used to bind the document so the reader can't see it. Ask your printing company for the right number for BCOR.

Open the PDF viewer and display a double page (use the version with the %). Then you can see: The outer margin of the left page (even page) and the right page (odd page) are the same. Both inner margins together are the same to one outer margin. The result is a very good typography.