Design Safety

Basically, I have been asked to design some t-shirts for a company and I said I would send over some examples of what I have done.
I was planning on showing the designs on t-shirt templates and then have the design clear on its own next to these.

I am sending the designs over to see what the company thinks and so they can decide if they like the designs and therefore pay me

My problem is how can I send these examples over and guarantee that they wont be stolen and used without my credit/payment.
I thought I could add watermarks etc, but thought I would see if anyone can help me further.

Also, save them out as pdf and when you are exporting mess with the security settings to limit the print quality, changes etc
Yes, the PDF security options are pretty good for the casual viewer. However, another option is to convert to a bitmapped image that can be printed out but even if the security is circumvented, they're not going to have much to work with. :thumb: