The counterparty’s counsel sent back one sentence: “we need a DocuSign certificate, not a drawing.” She was right about what her deal required. She was also describing a different product from the one I had used. I had put a visible mark on a page. I had not attached a signing certificate, a timestamp authority, or an audit trail. For that vendor and that contract, the mark was not enough. For the facilities form I signed an hour later, the same mark was exactly what the clerk had asked to see. The job is to know which document you are holding before you draw anything.
The stamp, mechanically
Sign PDF loads the PDF with pdf-lib. You draw on a canvas (line width 6, round caps), or you type a string that is previewed in a script face, or you upload an image. That bitmap is embedded and drawn onto the page you chose. The rest of the page content is the original page, not a JPEG rebuild. This is the opposite of the lock tool. Signing does not flatten the whole document into pictures. It adds a picture of a signature.
Anyone with a PDF editor can cover that picture, delete the image XObject, or export a page without it. A visible stamp is evidence that someone placed a mark. It is weak evidence of who, and it is not tamper-evident. If your process needs tamper evidence, you need a signing system that cryptographically signs the byte range. I do not pretend this canvas is that system, and I will not walk through forging one.
| Request in the email | This tool | What I tell the sender |
|---|---|---|
| “Sign at the bottom of page 4” | Fits | I will stamp page 4 and send a PDF |
| “Wet ink and mail” | Does not fit | Print, sign, scan |
| “DocuSign / Adobe certificate” | Does not fit | Use their envelope |
| “Initial every page” | Awkward. One placement flow, not a batch initialer | Confirm they truly want 40 marks |
Where I put the mark, and where I got burned
I draw on white space. Once I drew across a defined term because the signature line was crowded and the canvas felt roomy. The term was still in the text underneath, but the picture covered it on screen and in print. The other side asked if I had struck the term. I had not. I re-exported from the unsigned master and placed the mark lower. Keep the unsigned master. The signed file is a derivative.
Page order first. If you reorder pages after signing, the mark stays on the page object it was attached to, which may no longer be “the signature page” in the story you are telling. Freeze the order. Then sign. Then, if the file must travel under a password, lock a copy knowing that lock will repaint every page, signature included, into JPEG. Check the stroke after that repaint. A thin pen becomes a broken pen at JPEG 0.92 if you drew too small.
Typed signatures are text rendered to an image in the preview, then stamped. They look like a font, not like a biometric sample. Some clerks reject them. Some prefer them. I ask. Drawing with a mouse looks like a mouse. A trackpad looks worse. If I care about the shape, I draw on a phone or I upload a crop of a scan of a real signature, made once, stored locally, not in a chat thread.
A form I actually completed
Four pages, initials not required, signature block on page 4 with a printed name and date beside it. I filled the name by editing the source before export, because this tool does not fill form fields. It only stamps. Date I typed into the source the same way. Then I stamped the block, zoomed to 200%, and checked I had not covered the date. Download name: access-form-signed-2026-04-14.pdf. Unsigned master kept as access-form-blank.pdf. I did not lock it. The recipient was a front desk that prints and files. A password would have been a phone call I did not want.
The contract counsel’s document went into their signing envelope instead. I did not send them the stamped PDF “in the meantime.” Two versions of a signature in one deal is how people argue about which one controls. One process. Finish it.
If the PDF is encrypted, the signer cannot load it. Unlock a copy you are allowed to sign, sign that, and do not leave the unlocked unsigned copy in the sent folder. The sent folder should contain the signed file you meant to send and nothing that is half a step earlier.
Zoom is the review. A signature that looks fine in a thumbnail can sit on the wrong line. I open the downloaded file in a reader, not only the browser tab that produced it. Different viewers clip slightly differently. If the mark is clipped, I move it and export again from the master. I do not “nudge” by cropping in an image tool. That would turn the page into a picture and throw away the text layer the stamp had preserved.
Initials on every page are a process smell. If they insist, I would rather have a system built for that than hand-place forty stamps at midnight. Fatigue is how page 17 gets skipped and page 18 gets two. Count them.
The stamp that covered a date because the page was landscape
The signature block sat in the corner of a landscape certificate. I placed the mark using a portrait habit, too low, and it sat on the printed date. The preview in the tool was a small canvas. The page was wide. I had mapped the position badly. The fix was the unsigned master, a higher placement, and a download I opened at 100% rather than fit-to-width. Fit-to-width makes a landscape page look short and the mark look correctly parked when it is not. I now check landscape pages at 100% before I send. Portrait pages are more forgiving of my bad eye.
Two signers: I do not stamp both names in one session and call it countersigned. The second person should place their own mark, or the process is “someone drew two pictures.” Some internal forms accept that. I label the file with who actually drew. signed-by-me-awaiting-jo.pdf stops Jo from thinking the second scribble is already theirs. I drew only mine. The file name is the status. A status buried in email does not travel with the attachment when someone forwards it.
If the only instruction is “send it back signed today” and the document is a lease, I ask what kind of signature they will accept before I draw. Five minutes of asking has saved me from a stamped PDF that a registry rejected. The facilities form did not need the question. The lease did. The tool cannot tell those documents apart. The filename might. The email from their counsel definitely can. Read that email before the canvas, not after you have already attached the drawing.
I also keep the canvas clear between documents. A leftover stroke from the previous file is easy to stamp onto the next one if you do not hit clear. I clear, I look at an empty pad, then I draw. The cost of skipping that is a signature that is not mine on a form that is. Explaining that to a clerk is worse than the two seconds clear takes.