PDFgear enables you to utilize various image stamp formats, including JPEG, PNG, and BMP. You can select from existing stamps or design your own.
For inserting a pre-made stamp into a PDF, click the ‘Stamp’ button under the Comment tab, choose a preset stamp, and then click the desired location.

Add the Preset Stamp to PDF
To customize a stamp, simply pick ‘Custom Stamp’ from the Stamp menu.

Custom Stamp in the PDF
This lets you input your preferred text and choose the font color for your personalized stamp. You can also opt to add a picture as a stamp to your PDF file.