How to Batch Convert RGB to CMYK in Photoshop
There is a fast and easy method to batch convert many RGB photographs to CMYK files by using Photoshop. This is a great way to save time as you don't have to open individual files, convert and then save to another folder.
First of all, open Photoshop and check the color settings (Edit > Color Settings) to make sure you have selected the best color profiles for where you are in the world; Europe, North America or Japan. The Adobe RGB (1998) color space provides a large gamut of RGB colors suitable for images that will be converted to CMYK. Choose a CMYK profile best suited for the final printing press conditions, such as coated or uncoated paper stock, and total area of ink coverage, such as 300% or 350%.
Next you will need to create an 'Action' for the conversion. First, open an image, then open the Action Tab (Window > Actions), click 'Create new action' button, name the action in the text field and click the 'Record' button.
Now it is recording, so select 'Image > Mode > CMYK Color', then hit the 'Stop' button in the Action Tab. The action is now created ready for the next step.
To batch convert a folder of images, just select 'File > Automate > Batch...' and the following window opens.
Choose the 'Convert RGB to CMYK' action from the drop-down list, choose the source folder where your images are stored, then choose a destination folder where Photoshop will save the converted images.
Click the 'OK' button and the batch process will start. How fast will depend on the number of images that need converting.
The action you created will be stored, so you only need to perform a new batch process the next time you need to convert a batch of images.