diff --git a/_preamble.tex b/_preamble.tex
index 29afb0a..96d7252 100644
--- a/_preamble.tex
+++ b/_preamble.tex
@@ -1,6 +1,7 @@
-\documentclass[twoside, a5paper, fontsize=11pt, parskip=half, DIV=calc,%
+\documentclass[twoside, a5paper, fontsize=10pt, parskip=half, DIV=calc,%
 headings=onelinechapter, openany, headings=optiontohead,%
-numbers=noenddot,footsepline=false]{scrbook}
+numbers=noenddot,footsepline=false,BCOR=10truemm]{scrbook}
+\usepackage[cam,width=158truemm,height=220truemm,center]{crop}
 
 \usepackage[ngerman]{babel}
 \usepackage{fontspec}