Aperture makes it easy to add a copyright to your images by including an option to add a watermark when you establish presets. The problem is that the colors of generic watermarks are hidden in some images and clash with others. Of course you could create watermarks in a variety of colors, but then you’d have to take the time to specify which one to use for each image you want to watermark. That defeats some of the convenience of using the presets.

My solution is to create a dimensional watermark that looks embossed and uses the colors in the image itself. To create a watermark for email pics do the following:
1. In Photoshop begin by opening a new file roughly the size of the email pics you normally send. For me that’s 600 x 600 pixels at 96 dpi.
2. Make sure to select a transparent background.
3. Next use the type tool to create a copyright. I like Snell Roundhand and use a font size of 24 pt.
4. In the Layers Pane add a Layer Style to the text layer. I use Emboss at the default settings, but you can opt to adjust the settings.
5. Next reduce the Fill level to zero. (If you leave it higher, then some of the original color you used to type in the information will show through.)
6. Crop closely around the watermark. If you leave a little space at the end of your name , the watermark will be placed back a corresponding amount from the edge of the picture.
7. Save the watermark as a Tiff file and be sure to enable transparency in the second save dialog that appears.
8. Open Preferences in Aperture and choose the Edit button by Email Export Preferences.
9. Click the option to add a watermark and choose the watermark you just created. I prefer it in the lower right corner. I’ve found that an Opacity of 0.5 works well for me. When the watermark is created this way and used for email pics I don’t need to use the Scale option.

You may need to create additional watermarks at other sizes for use with other Presets, but once you create them and set them up as presets, you can use them on any image.