How to stamp a PDF Approved or Draft
Add Approved, Draft, Confidential and dated stamps to a PDF with PDF by Zaweba, or make custom stamps from pictures and PDF pages in categories.

The Stamps list in the Comment menu of PDF by Zaweba has ready-made stamps, including Approved, Draft, Confidential and Sign here, plus dated stamps that carry your name and the time. Pick one, place it on the page, and turn or resize it as you like. You can also make your own stamps from pictures or PDF pages. The app is free and works offline on Windows.
A stamp says something at a glance, which is why offices have used rubber ones for so long. On a PDF it does the same job without printing anything.
Placing a ready stamp
Open the document, choose Comment, then Stamps, and pick the stamp you want. Place it on the page and drag it to where it reads best, usually the top corner of the first page or beside the signature line.
A dated stamp is the one to use when it matters who approved something and when. It carries your name and the time, so a document marked as received or approved shows both on its face. Set the name that appears on your comments first, so the stamp shows yours.
Stamps can be turned for that slightly skewed rubber stamp look, or to fit a gap. Use the round handle, holding Shift to turn in 15 degree steps, or Comment, Turn stamp.
Making your own stamps
Ready stamps cover common words, but many offices want their own: a company logo, a Paid stamp, a Checked by box, a department name. Custom stamps are made from pictures or from PDF pages. Design one in any drawing or layout program, save it as a picture or a PDF, and add it as a stamp.
Custom stamps are kept in categories you can make, rename and delete, so a long collection stays easy to pick from. You can import pictures and whole PDFs as stamps, which is a quick way to bring in a set someone else has made.
A PNG picture with a see-through background works best for a stamp that should sit over text, since only the ink shows.
Stamps are comments
A stamp sits on top of the page as a comment. That means it can be moved, turned or deleted, and it shows in the Comments panel, where you can filter by kind to see every stamp in a long document. Double-click it to open its pop-up and add a note, such as conditions of an approval.
Because it's a comment, someone else could also move or delete it. When the stamp should become part of the page, flatten comments. That draws the stamp into the page and removes it as a live object.
When a stamp isn't enough
A stamp shows a decision; it doesn't prove who made it. Anyone can put an Approved stamp on a file. Where proof matters, sign the document with a digital ID from the Sign menu after stamping it. A digital signature records who signed and shows any change made afterwards.
Also think about Draft stamps on documents you plan to finalise. Take the stamp off, rather than covering it, before you send the final version.
PDF by Zaweba keeps your stamps on your PC and works without a connection, so a stamp library built once is always to hand.