How to: Using Mac Automator to watermark images using a folder action

One of the challenges I face as a photographer is having my photography lifted by fans, parents, bloggers and others. Other photographers will understand my frustration: You invest tens of thousands of dollars in equipment, invest hours of time and energy in producing images, only to have them stolen. An unfortunate side effect of this is the need to watermark images.

Watermarking photos typically requires an application to implement but Mac users can use built-in Automator tool to make watermarking photos as easy as dropping files into a folder.

Below I present instructions on how to use Automator on Mac OS X 10.11 to resize and watermark photos.

Here is what you need

  • Mac OS X 10.11 “El Capitan” (the instruction I write below are for 10.11, but likely could be modeled for future or earlier versions)
  • The Image Processor action [find it here] which as created by photographer Ryan Britton.
  • A PNG-24 overlay file to use as your watermark
  • You don’t need a separate application like Photoshop.

What the Automator action you create will do

  • When you copy or “drag and drop” photos to a special folder (“watched folder”), Automator will automatically watermark and resize the photos, and save them to a separate folder.
  • It will not overwrite your original files.
  • You can either only watermark, only resize photos, or both.
  • You can define the output color space.
  • Using Automator will usually be faster than opening up a separate application to watermark photos.

How you might use it

  • By dragging and dropping files into the watched folder.
  • By saving files from Photoshop to the watched folder to allow Automator to process them.
  • By copying files from applications like Photo Mechanic to the folder to process them. (I personally don’t like using PM to watermark files because I’ve found the image overlaid will be at different widths, depending on if you use watermark a portrait or landscape photo. With this action the watermark is a consistent size.)


Create a folder on your computer to serve as the watched folder. I have called it “Watermark Automator” on my desktop, but you can call it whatever you want and save it wherever you want.

In the watched folder create a subfolder where the images saved by Automator will be saved. I call it “!output”. I create a folder leading with “!” so that when the folder sorts alphabetically, the output folder is always at the beginning.


Open Automator.

Click “File”, “New” and “Folder Action”


Drag the Image Processor file you downloaded from the requirements section above to the Automator icon in your task bar. Automator will ask if you want to install Image Processor. Say “Install”.


You will now see “Image Processor” appear under the Photos section of actions in Automator. Drag this process to your work flow on the right. You may need to activate the action in Automator since it is a downloaded Internet file.


As shown above, use the dropdown menu above the action to select what your watched folder is. (If you don’t make your selection, the action will not work because Automator will not know which folder it is supposed to “watch” to trigger the action.)

In the Image Processor action, select the output directory for where you want the images saved to. I made this “!output”, a subfolder of my watched folder, but you can save it anywhere you want; it does not need to be subfolder of your watched folder.

I keep “Output format” as “Save as original” with “Preserve metadata” turned on, and “Output ColorSpace” as sRGB. Select what is best for you. For scale, I use “Fit within dimensions” with 2000 pixels as both the length and width, ensuring that the longest edge of the image is always 2000 pixels.

I then select my watermark image by selecting “Other” in the “Watermark” dropdown menu and selecting where on my computer the PNG watermark file is. (FWIW, my watermark image is 800 pixels wide by 190 tall. Since the action cannot adjust transparency of the watermark, I created my PNG file to be 70% transparent in Photoshop. Also of note, the watermark is not scaled up or down by the action; it will be overlaid at 100%. Thus, if your watermark is 2000 pixels wide, and the width of your photo is 2000 pixels, the watermark will occupy the entire width of the photo. I personally find that a 800 pixel-wide watermark for either a landscape or portrait photo at 2000 pixels wide works well.  The creation of the PNG file is beyond the scope of this article.)

I select the bottom left as the anchor with 20,20 as offset. Put your watermark where you prefer.

(I’ve not yet used the “Copyright” option as I was not clear on how to use it.)

Click “File” and “Save” and save the file as “Image Processor Watermark” or whatever name you prefer. Automator will automatically save the action to: /Users/[username]/Library/Workflows/Applications/Folder Actions.  Leave it there. If you ever need to tweak the action (changing the overlay file, the scaling, etc.) just go to that folder and open up the action, make changes, and save.)

Here is what my full workflow looks like after completion.


Drop an image file into the watched folder to test it out. If you find that nothing happens try fixing this by right clicking on your watched folder, select “Folder Actions Setup” and then select “Enable Folder actions” and make sure your new action is selected to activate it. Also make sure you have properly told Automator which folder to watch, and the action which folder to save to.

Here is what an image looks like after watermark using Image Processor.


I hope you found this tutorial helpful!