How to Add Watermark to PDF in Preview on Mac
1. Open the PDF file you want to add a watermark to in Preview. 2. Click on the 'Edit' menu and select 'Insert' followed by 'Text'. 3. Type your desired text or upload an image to use as a watermark. 4. Adjust the position, size, and transparency of the watermark. 5. Save the PDF file with the newly added watermark.