What is the PSG file format?
A .psg file is an AFP (Advanced Function Presentation) page segment - a reusable binary resource used in IBM high-volume print systems. Page segments are pre-composed objects such as a company logo, a signature, a stamp, or a barcode, stored once and referenced many times across the pages of a large print stream.
The format follows the AFP/MO:DCA (Mixed Object Document Content Architecture) standard, first published by IBM in 1984. Every structured field in the file opens with the byte 0x5A - the universal AFP structured-field introducer - followed by a length field and a three-byte field identifier. A page segment begins with a Begin Page Segment (BPG) structured field and closes with an End Page Segment (EPG) field. Inside, the content may be IOCA raster image data, GOCA vector graphics, BCOCA barcode objects, or coded text, all encoded in big-endian binary.
.psg files are produced and consumed by AFP composition and print management software rather than by end users directly. They are managed as assets alongside other AFP resources such as .ovl overlays and .fnt font files. Common environments include IBM z/OS and IBM i (AS/400) mainframe print workflows, where millions of transactional documents - bank statements, insurance policies, utility bills - are generated each day. AFP Workbench Viewer and OpenText AFP tools can display .psg resources.
Security & safety
RISK: LOWPSG is a passive binary data file with no executable code. It is an enterprise IT format; no known malware uses this extension or format. The main risk is data corruption in legacy migration workflows.
Format details
in a nutshell- PlayStation Save Game (various) - Some PlayStation emulators and game utilities use .psg for save-game or memory card data files; unrelated to IBM AFP.
Programs that open PSG files
Windows2 apps
AFP Workbench Viewer
Paid Enterprise AFP viewer/editor from Broadcom (acquired from ASG); open PSG to view the page segment content.
Optio / OpenText AFP tools
Paid OpenText Output Transformation Server and related tools read/convert AFP streams including PSG resources. 
Linux1 app
afptools / libafp (open source)
Open-source Community tools for parsing and inspecting AFP structured fields including PSG resources on Linux. Technical details
deep spec| Standard | AFP/MO:DCA (Mixed Object Document Content Architecture - Presentation) |
| Developer | IBM (standard published 1984 with Advanced Function Presentation) |
| Magic byte | 0x5A at offset 0; universal AFP structured-field introducer byte |
| Byte order | Big-endian (IBM mainframe convention) |
| Content types | IOCA raster images, GOCA vector graphics, BCOCA barcodes, or coded text |
| Begin/end delimiters | Begin Page Segment (BPG) and End Page Segment (EPG) structured fields |
| Compression | None at container level; internal IOCA raster data may use IBM MMR/G4 or JPEG |
| Typical size | 1 KB-10 MB (text objects are small; raster images can be large) |
| Operating environments | IBM z/OS, IBM i (AS/400); also readable on Windows and Linux via AFP viewer tools |
| Usage pattern | Reusable resource referenced repeatedly across pages; not an end-user document format |
| Common content | Company logos, signatures, stamps, and barcodes in high-volume transactional print streams |
| Color depth | 1 bpp (bilevel IOCA) to 32 bpp color, depending on enclosed image content |
| Released | 1984 (AFP / Advanced Function Presentation first published by IBM) |
| Open standard | Yes · royalty-free |
| Specification | www.afpconsortium.org |
PSG conversions
Community Q&A
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