The time finally came to put a new watermark on my website images. I thought maybe I should share my technique with you! I don't do any kind of batch processing but I feel like this is very fast while still leaving me in control. I use Photoshop because that's what I'm always using.
My little tutorial uses finished .png images, already edited, sized and ready for the web.
Copy (not move) all the .pngs into a new folder where you want the finished watermarked images to live.
Open them all in Photoshop (10-15 at a time, if you have too many).
1. Design the watermark. Here you can see I've made a master psd file (on the right) by renaming one of the correctly-sized images and then adding part of my logo. Keep this watermark on a separate layer. Turn the opacity down if you'd like. (There are all kinds of styles you can apply at this point: embossing, drop shadows, whatever fanciness you have in mind - do it now. I just wanted simple.)
2. shift-drag the watermark layer into your next image* (Shift keeps it aligned.)
3. command e (merge down)
4. command s (save)†
5. command w (close)
6. repeat starting at step 2.
*If you need to move the watermark around you can do that now.
†This is saving a flattened version and the watermark is no longer editable. That's why I copied all my images into a new folder first. I can still go back and get the unmarked ones when I need them.
•For PC users, replace "command" with "control.
This process can go very fast once you get started. (I think writing this blog post took longer.) I wanted mine all to match so I only had to move the watermark on two images. I hope this is helpful! If you have a different procedure you love, leave a comment!