Open your album in Organizer.
Setting a Watermark
You can select images individually by simply clicking the box at the top of each image. To select a range, just check the first and last images in the range. When you check the last image, hit shift at the same time and you will automatically select all the images in between.
Then, go to the Actions menu and click Watermark.
You have a number of different options for customizing your watermark. For example, you can modify the font, position, color, size and opacity of the text. Or, if you have an image logo that you would like to add as your watermark, click Upload Image and select the image from your files. You can also create watermark presets.
View your photos in the Organizer or the Gallery to see the watermarks added to the selected photos.
To see the difference between watermarking the whole album and individual photos, visit this article.