Acrobat User Community Forums

Yes. You need to create the stamp in a program like Adobe Illustrator or Adobe Photoshop. In Illustrator, leave the file as vector art and leave all the areas you want to appear as transparent without any color including white. The transparent areas will appear as transparent when you convert to PDF and create the custom stamp.

If using Photoshop, add your image artwork to a layer and define all the transparent area without any color (pixels). Convert the layer PSD file to a PDF document. All transparency is preserved.

ted

As I indicated in my first repsonse, you need to use a program like Adobe Illustrator or Adobe Photoshop. If you use Adobe Illustrator, be certain to not fill the objects with white as you draw them. Be certain  no color is applied to the objects you want to make transparent. You can then save as PDF or save as a .ai file and add the file as a custom stamp.

If you are using Photoshop, make sure you have the artwork on a Layer. You need to make sure you don't see Background appear in the Layers palette. When you erase (or use the Magic Wand and delete  a selection), you should see the transparency grid in the areas you want to remain transparent. Make sure to NOT flatten the artwork and leave it on a layer. When you save to a Photoshop PDF file, the transparency will be preserved. If you have any difficulties follow these methods, let me know what program you're working in if you post another comment.