Saving PDF to maintain download size

[waters_tc]

I've been toying with releasing some of my artwork as higher res PDF's for download, but I want to make sure the user can't take that PDF and adjust the print size.  So, it can only be printed the size I've saved it too.  So, far I haven't been successful- as I can take the downloaded PDF and dump it on Photoshop and change the size.  Is there a setting I'm missing?

[try67 · Accepted solution]

No. This is not possible to achieve. A PDF can be printed to any size the user wants it to be printed to.

If you don't want the recipients to be able to print a high-quality version of your artwork then don't give them a high-quality version of it.

[waters_tc]

Well, of course- but the whole point is to have a "product" which is a downloadable image that prints beautifully at a specific size.  And as my testing has shown and the first part of your answer confirms, there isn't a way to do that.

[try67]

I mean, if your artwork is not a vector image then scaling it up will cause it to be pixelated, like any bitmap image. So if you adjust the resolution of your image to the size you want it to be printed at you can make it more difficult to blow it up, but you can't completely prevent someone from doing it.