1. From any sheet, select the stamp tool
2. Click on the stamp sticker
3. Select Custom Stamps
4. To add Custom Stamps, click on Import Stamp to browse the stamps on your device
5. Select the desired stamp by clicking Open
6. Click on the stamp to apply it to the sheet, you can choose to add the current date, your name or give the stamp a transparent background by clicking on the options. A blue checkmark will appear when selected.