Locking A PDF Presentation
If you're using Photoshop to create a PDF Presentation slide show (under the Automate submenu in the File menu) so you can email it to your clients for proofing, one of your concerns may be that your client will just print your photos out to a photo-quality printer, leaving you out in the cold (so to speak). But you can pull the plug on their printing aspirations. When saving your PDF Presentation, under Output Options, choose Presentation, then hit Save. It'll ask you to name your PDF presentation (you're not done yet), so name it and click Save. Then, a PDF options dialog will appear. Under Security (in the options along the left side), turn on the checkbox for Use a Password to Restrict Printing, Editing and Other Tasks under Permissions. Enter (and memorize) a password. Then, make sure Printing Allowed and Changes Allowed are set to None. Click Save PDF and it'll ask for your password one more time. Now, when you email the PDF Presentation, printing will be grayed out, and even if they have the full version of Acrobat, they won't be able to copy-and-paste your photos into something else for printing.