Restrict permissions by setting the document a password.

If you use Adobe Acrobat, is is advisable to first make a backup copy of the PDF document. This way the document will be available even if you forget the protection password. You will then have both an editable version and a delivery version of the document.

PDF-Xchange PDF Tools does this as part of the process.

How to do it using different applications:

PDF tulostuksen ja muokkauksen esto