hi
have you tried using corel help file search for (mirror text)
should show you symbol to find.
have used corel 11 but not for a while but i know it was easy todo.
using x3 now but probably still the same make sure what you want to mirror is selected first then there should be a mirror symbol on bar or
goto arrange/transformations choose scale should be there but again remmeber to have text selected aswell.
hope this helps
ps
if the file is going to printers surely they can mirror it there end
Bookmarks