theapk · ghostprint

Tag a 3D print.
Invisibly. Forever.

Pin a printed part to a specific order, printer, and timestamp — without changing the visual, dimensional, or surface finish of the part. Two independent watermark layers, both round-trip verifiable.

1 · Pick your file

Drop your .stl here or click to choose
Up to 50 MB · STL files only
no file selected

2 · Label this print

leave blank to use the current time
These details get stamped invisibly into the file. Later, anyone with the original can drop in a suspect part and check it matches.
waiting for file

3 · Download


    

  

  









  

    
How it works

    

      L1 — G-code watermark. A 12-byte payload (printer + job +
      timestamp) is encoded into sub-resolution Z-babysteps at the start
      of the print, duplicated in a comment block. Survives any
      post-processor that doesn't strip ; comments.
    

    

      L2 — Geometric steganography. Per-vertex perturbation of
      ±0.005–0.020 mm driven by a BLAKE2b hash of the order ID.
      Below typical 0.04 mm nozzle X/Y resolution. Hold the master
      STL to verify any part, any time.
    

    

      Both layers ship in the same CLI (tag-print.py)
      and the same web tool. The MIT CLI is the source of truth; the
      web is a convenience layer for non-technical makers.
    

  


  

    
Pricing

    

      

        
CLI

        
$0

        
    
          
  • MIT-licensed Python
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  • Tag + verify offline
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  • No upload, no tracking
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  • Two watermark layers
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        Download CLI →
        
pip install theapk-ghostprint (v0.1)

      

      

        
Maker

        
$9 / mo

        
    
          
  • Drag-drop web tool (this page)
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  • Hold master STLs in your account
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  • Verify suspect parts in the browser
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  • Up to 500 tags / month
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Studio

        
$49 / mo

        
    
          
  • Unlimited tags
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  • Multi-printer fleet dashboard
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  • API access + per-order webhook
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  • Bulk verify a print run
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