We all know that clients can easily crop a watermark off of a low-res file you deliver to them, but unless they have Photoshop or Photoshop Elements (or similar), and are skilled at up-sampling, there is an easy way to prevent your clients from ordering even small prints from a lab.
I just did a little experiment to see exactly what size I would need to prepare my low-res watermarked images at to prevent printing.
I created three different sizes and dpis, and uploaded each to Shutterfly.
The size that wins the ‘prevent your clients from printing war’ is this: 600×400 px, at 5dpi.
I got an error message with each size print I tried to order, all the way down to 4×6 prints, with the exception of wallets. (The image on top was the 600×400 at 5dpi, the image on the bottom was 700×450 (?) at 10dpi.)
Note that the 600×400 size is still perfectly adequate for displaying in an album on Facebook for example. This is it:
Of course, this goes without saying that you have your copyright information in the metadata for each image, and include a file on their DVD/thumb drive with your copyright information and use permissions, but using the above tip your client will be prevented from ordering prints, regardless of whether they understand/agree with/read your copyright or crop off your watermark. (It’s also a good idea, if you are really concerned with this or it has been a problem with your business, to include ‘copyright jane smith’ [your name] at the end of every filename). I know every lab is different, but I’d think that even if they didn’t get an error message upon checkout, or delivering a thumb drive to Costco (or whatever), that the lab would contact them upon discovering their prints will look horrid printed at that resolution. Sure, some may go ahead and place the order and hope for the best, but at 5dpi, their dreams of ignoring your copyright will be shattered once they get the awful, pixelated, blurry prints in the mail. Mwah ha ha.
Just wanted to pass that along, because I know the conversation has come up lately about clients printing low-res files! If you have your own different tips on how to prevent a client from printing your low-res watermarked file, leave it as a comment below!