The add-stamp tool pre-fills the stamp text field with the word APPROVED, which the user can overwrite with custom text.
Type your custom label into the stamp text field.
Adobe's official stamp guide notes that a stamp's contents cannot be altered after it has been applied to the page. Add and modify stamps in Acrobat | Adobe Acrobat
Add StampCustom Approved Stamp Text PDF
The add-stamp tool limits stamp text to at most 40 characters, enforced by both the input field and server-side validation.
Review the typed text to match your intended label.
Checking Character Limits
The add-stamp page's stamp text input carries a maxLength attribute of 40 characters.
Count the characters in your custom label before submitting.
Verifying Custom Text Rendering
Open the downloaded PDF and select the stamp text to check for a text layer.
Compare the rendered stamp against your typed label.
Continue with Red Box Color Fixed or Stamp vs Watermark Difference.
Frequently Asked Questions about Custom Approved Stamp Text PDF
How do I change the default stamp text?
Overwrite the pre-filled APPROVED text with your own label.
Where do I type the custom text?
Enter your label in the stamp text field.
How do I stay within the character limit?
Keep your custom label under 40 characters.
How do I verify the stamp looks correct?
Download the PDF and inspect the stamp area.