Signed by Ghostly

Invisible signatures for your 3D print files.

Sign your 3MF and STL files before you sell them. They look and print exactly the same. When a copy turns up somewhere, Ghostly proves it's yours and shows which copy it came from.

Works with 3MF and STLNothing changes in the print

Check a file Signature found
castle-dice-tower.3mf6.1 MB, found on a free model site
Signed by Ghostly
Owner
3MF Labs
Design
Castle dice tower
Copy
Etsy
Registered
October 30, 2026
Made for designers who sell on
EtsyCultsMakerWorldPrintablesPatreonGumroadtheir own shops

You sell a file once. Then it travels.

It gets uploaded to free sites, bundled into "mega packs" and sold again under someone else's name. Proving a file is yours usually comes down to screenshots, dates and a lot of arguing.

Ghostly gives every copy you sell a signature that only shows up when you check for it.

Three steps. No new habits.

You keep designing and selling the way you do now. Ghostly fits in between.

Sign

Upload your file

Drop in a 3MF or STL and pick the copies you need, like your shop, Etsy and Patreon. A small model takes about two minutes.

Sell

Sell it like always

Download your signed copies and list them as usual. Each copy carries its own invisible signature, so they can be told apart later.

Check

Check any copy you find

Found your design somewhere? Drop the file into Ghostly. It tells you if it's yours and which copy it came from.

Built to hold up.

People change files they didn't make. Ghostly was built and tested with that in mind.

Survives everyday edits

We test by damaging signed files the way people really do, then checking them again. Ghostly still recognized the design after every edit below, and in most cases it still named the exact copy.

  • Saved as STL
  • Moved and turned
  • Scaled
  • Simplified
  • Cut in half
  • Several of these at once

Tested on real models sold by 3MF Labs.

  • Prints the same

    Every signed copy is test-sliced against your original before you get it. If anything would print differently, Ghostly leaves the hidden part out and tells you.

  • Knows the copy

    Your Etsy copy and your Patreon copy carry different signatures, so you can see where a leak started.

  • More than one kind of proof

    Each signed file carries several separate kinds of evidence. Remove one and the others still answer.

  • Nothing to see

    No logo stamped into the model, no extra parts, nothing a buyer can see or feel.

Why we don't explain the trick.

We'll tell you everything Ghostly does. We won't publish how the signature is made, where it sits or how a check decides. A signature with public instructions is a signature someone can learn to remove.

So results stay plain: whose design it is, which copy, and when it was registered. Nothing that would help anyone fake one or strip one out.

Say it on your listings.

Every plan comes with the Signed by Ghostly badge for your listings and shop pages.

Buyers see that you take your work seriously. Anyone thinking about reselling your file sees it too, and knows the copy can be traced.

Low-poly crystal, 3MF and STL
Instant download$4.50
Signed by Ghostlysignedbyghostly.com

Simple plans.

Start free. Upgrade when you're signing more than a few designs.

Free

$0forever

Try it on your own files

  • 3 signed designs
  • 2 copies per design
  • 10 checks a month
  • Certificates and the listing badge
Join early access

Creator

Most creators
$9/ month

Billed monthly

  • 40 new designs a month
  • Up to 4 copies per design
  • 200 checks a month
  • Certificates and the listing badge
Join early access

Studio

$29/ month

Billed monthly

  • 200 new designs a month
  • Up to 10 copies per design
  • 1,000 checks a month
  • Priority signing queue
  • Certificates and the listing badge
Join early access

Planned pricing for launch. Compare plans

Questions creators ask.

Will my files print differently?

No. Every signed copy is test-sliced against your original before you download it. If signing would change how a copy prints, Ghostly leaves the hidden part of the signature out of that copy and tells you, so the file still prints exactly like your original.

Can someone remove the signature?

Nothing hidden in a file is impossible to remove, and we won't pretend otherwise. Ghostly makes it hard: each file carries several kinds of proof, and the everyday edits people make don't remove them. Keeping the method private keeps it that way.

Does Ghostly stop people copying my files?

No tool can stop a determined person from sharing a file. Ghostly makes it provable that a copy is yours and shows which copy it came from, so you can act on it with evidence instead of guesses.

Which files work?

3MF and STL, or a ZIP of them, up to 150 MB per upload.

More questions and answers

Be first in line.

Ghostly is opening to creators in small groups. Leave your email and we'll tell you when your spot is ready.