What is the PDO file format?
A .pdo file is a digital papercraft document created with Pepakura Designer, a software tool developed by Tama Software. Papercraft is closely associated with Japanese culture, and Japan is where the software - which allows users to transfer 3D model data onto a paper sheet - was created. A single .pdo file contains the 3D model and its corresponding cutout, with marked cut and fold lines.
Projects stored as .pdo files are used for printing designs on paper sheets. A 3D model created in Pepakura Designer - often imported from OBJ or STL files - is transformed into the 2D cutout needed for the paper figure. The format is a proprietary binary with no published specification. Completed layouts can also be exported to PDF, and both Pepakura Designer and the free Pepakura Viewer run on Windows.
Security & safety
RISK: LOWA .pdo is a passive model/data file with no executable code, so opening one in Pepakura Viewer/Designer is safe. The only real caution is download source: get the Viewer and Designer from Tama Software's official site, not from random "free download" portals that bundle adware. Community templates shared as .pdo are generally harmless, but as always download from reputable papercraft communities.
Format details
in a nutshellFULL NAMEPepakura Designer Document
DEVELOPERTama Softwaresince early 2000s (Pepakura Designer by Tama Software, Japan)
CATEGORYData Files
MIME TYPEapplication/octet-stream
TYPEpapercraft model file - unfolded 3D mesh with printable 2D pattern (binary)
This extension is also used by…
- Panasonic / Olympus camera RAW (PDO/ORF variants) - A few legacy camera utilities used .pdo for processed image data - unrelated to papercraft; rare today.
- Oracle Process Definition / proprietary app data - Some business/CAD applications have used .pdo for internal data; these are app-specific and unrelated to Pepakura.
Programs that open PDO files
Windows2 apps
Pepakura Designer
Paid Open, edit, rescale and unfold .pdo files; import 3D models (OBJ/STL/3DS) and export PDF/SVG. Required for creating or modifying patterns. 
Pepakura Viewer
Free Install the free Viewer (Tama Software), open the .pdo, rotate the 3D model and File → Print the 2D pattern onto cardstock. View-and-print only - can't edit. 
macOS1 app
Pepakura Designer / Viewer (via Wine/Parallels)
Paid No native Mac build - run the Windows Viewer/Designer through Wine, CrossOver or a Windows VM (Parallels). Otherwise ask for a PDF export of the pattern. 
Linux1 app
Pepakura Viewer (via Wine)
Free Run the Windows Pepakura Viewer under Wine to open/print .pdo; no native Linux opener exists. Technical details
deep spec| File structure | Binary proprietary format; no published specification or open schema |
| Embedded data | Stores the original 3D mesh and its fully unfolded 2D sheet layout in a single file |
| Fold-line encoding | Encodes mountain and valley fold lines with distinct dash styles for printed guidance |
| Tab and flap data | Records gluing tabs and flap geometry for step-by-step paper assembly |
| Texture and colour support | Embeds texture and colour data from the source 3D model for full-colour print output |
| Part numbering | Stores edge-match codes and part IDs so printed pieces can be joined in the correct sequence |
| File locking | Supports password protection; locked files open in Pepakura Viewer for printing but cannot be edited |
| MIME type | application/octet-stream (no registered subtype) |
| File identification | Identified by extension; begins with a proprietary version-string header, no stable magic bytes |
| Platform support | Native Windows only; runs on Linux and macOS via Wine or Parallels |
| Format versions | Multiple internal version revisions; newer file versions may be unreadable by older software releases |
| Scale settings | Stores real-world scale data so the assembled paper model matches the intended physical size |
| Primary applications | Pepakura Designer (paid, full editing) and Pepakura Viewer (free, view and print only) |
| Source geometry imports | Accepts 3D input from OBJ, STL and DXF mesh formats before unfolding into a flat pattern |
| Released | early 2000s (Pepakura Designer by Tama Software, Japan) |
| Specification | pepakura.tamasoft.co.jp |
PDO conversions
Possible
.PDO .PDFGUIDE
Yes, PDO files can be converted to PDF -- the fastest method is File > Export > PDF in Pepakura Designer, or…
How to convert
.PDO .OBJGUIDE
Yes, Pepakura Designer (paid) can export the 3D model inside a PDO file directly to OBJ via File > Export.
How to convert
.PDO .STLGUIDE
Yes - Pepakura Designer (paid) exports the 3D mesh from a PDO file to STL directly via File > Export.
How to convert
.PDO .SVGGUIDE
Yes, PDO can be converted to SVG using Pepakura Designer (paid); there is no free alternative.
How to convert
Community Q&A
asked by usersNo questions yet - be the first to ask about PDO files.
Frequently asked questions
How do I open a PDO file?
On Windows, install the free Pepakura Viewer from Tama Software - it opens any .pdo, shows the 3D model and lets you print the flat pattern. To edit or unfold models you need the paid Pepakura Designer.
How do I open a PDO file for free?
Use Pepakura Viewer (free, Windows) to view and print. It can't edit the pattern, but for printing a downloaded papercraft template that's all you need.
How do I open a PDO on Mac?
There's no native Mac version. Run the Windows Pepakura Viewer/Designer via Wine, CrossOver or a Windows VM (Parallels), or ask the template's creator for a PDF export, which opens on any device.
How do I convert a PDO to PDF?
In Pepakura Designer use File → Export → PDF. With the free Viewer you can instead Print and choose 'Microsoft Print to PDF'. A PDF is the easiest way to share or print the pattern at a copy shop.
Can I print a PDO without Pepakura Designer?
Yes - the free Pepakura Viewer prints the pattern. You only need the paid Designer if you want to edit, rescale or create your own unfolds.
What program made my .pdo file and what is it for?
Pepakura Designer (Tama Software). PDO files are papercraft patterns: a 3D model unfolded into numbered flat pieces you print on cardstock, then cut, fold and glue into a paper model - widely used for cosplay armor, helmets and props.
References
1Tama Software - Pepakura Designer (official)pepakura.tamasoft.co.jp
2Tama Software - Pepakura Viewer (free) downloadpepakura.tamasoft.co.jp
