# How to add plots into an existing ps file

Hi,
I am trying to add new plots to an existing ps file. I think the code

``````TPostscript ps;
ps.Open("myOldPs.ps");
ps.On();
....
ps.Close();``````

should work because I just open the existing ps file. But in fact, my old ps file always is overwritten and created newly. Anybody could give me hints how to solve the problem? I don’t like the way of merging ps files.

Thanks,
Zhiyi

Once a postscript file has been closed it cannot be open again in update mode.
For writing multiple canvases to a ps file read section
"Writing several canvases to the same Postscript file"
at :http://root.cern.ch/root/htmldoc//TPad.html#TPad:Print

Rene