Hi PTC Community !
This is my first (and long... sorry) post. I write because I have been spending the last two years to solve a problem that is easy do describe :
How do I get a good display of the hidden lines on PDF files with the SaveAs PDF command ???
I still could not get the answer 
...
First of all there are two ways to get a PDF file from a detailed drawing :
1) File --> Print. Select "MS Printer Manager", then OK and select your "PDF printer" in the "Name" field. Here is what I obtain with my "Adobe PDF" program :
As you can see, the dashed hidden lines are well displayed and are BEHIND the black solid lines that describe the shape of the object.
If you modify the plot_linestyle_scale parameter, the size of the hidden line changes. Here is what happens when I change the value from 3 (previous picture) to 1 (next picture).
Now the hidden lines appear with smaller elements.
With this method, all is ok 
.
2) Click on the SaveAs PDF button in the toolbar :
Here is what I obtain :
As you can see, the dashed hidden lines have very long elements (they seem to be solid) and, if you look carefully, they appear IN FRONT of the black solid lines, in the same way as already described in the thread http://communities.ptc.com/message/158760. The black solid lines are also thinner than with method 1.
If you modify the value of "plot_linestyle_scale", there is NO modification.
In other forums where this problem of hidden lines style is described, people confuse the two ways to get the PDF and say : modify the "plot_linestyle_scale" to get your result...
As I said, my question is : How do I get a good display of the hidden lines on PDF files with the SaveAs PDF command ???
More generally :
How do I modify the appearance of the drawings processed with the "SaveAs PDF" command ?
For technical reasons, I need to use the method number 2. So, please, don't say "Sylvain, use method 1" 
.
Thread http://communities.ptc.com/message/158760 could not help me, as it uses File --> Print method.
I use ProE WildFire 4.0
Thank you !