Image MIME Reference
CLIP
Clip Studio Paint Document
image/vnd.clip
VS
Portable Graymap
image/x-portable-graymap
PGM
A complete technical comparison of Clip Studio Paint Document and Portable Graymap — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | CLIP | PGM |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | Yes | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | Yes | ✕ No |
Clip Studio Paint Document
image/vnd.clip
Extension
.clip.lip
Container
SQLite 3 Database
Compression
Proprietary Blob Compression (within SQLite)
Algorithm
Proprietary (Celsys Blob Encoding)
Color Depth
8-bit (Monochrome), 8-bit (Grayscale), 24-bit (RGB), 32-bit (CMYK)
Developed by
Celsys, Inc.
Released
2012
Magic Bytes
53 51 4C 69 74 65 20 66 6F 72 6D 61 74 20 33 00
Portable Graymap
image/x-portable-graymap
Extension
.pgm
Container
Netpbm
Compression
Uncompressed
Algorithm
None
Color Depth
8-bit (Grayscale), 16-bit (Grayscale)
Developed by
Jef Poskanzer (Netpbm Project)
Released
1988
Magic Bytes
50 32 (ASCII) or 50 35 (Binary)
Browser Support Comparison
| Browser | CLIP | PGM |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
CLIP
CLIP Strengths
- SQLite backend provides incredibly robust data integrity, preventing catastrophic project loss if the application crashes during a save
- Allows for massive multi-page comic projects and animation timelines to be handled efficiently without loading the entire project into RAM simultaneously
- Industry standard for manga, anime, and webtoon professional workflows
Limitations
- Heavily closed-source and proprietary, meaning no third-party applications (like ImageMagick or GIMP) can parse or render the files
- Standard MIME identification tools will misidentify the file as a generic SQLite database, causing friction in automated file-upload validations
- Zero web browser support
PGM
PGM Strengths
- Extremely simple format allows custom parsers to be written from scratch in minimal time
- Supports 16-bit precision, making it highly valuable for scientific, medical, and height-map data where 8-bit precision is insufficient
- ASCII encoding ('P2') allows manual editing and visual inspection of pixel values directly within a text editor
Limitations
- Strictly limited to grayscale; cannot display color
- Lack of compression results in massive file sizes, making it entirely impractical for web delivery or consumer storage
- Does not support alpha transparency or modern metadata structures
When to choose which format
CLIP
Use CLIP when…
- Digital Illustration and Concept Art
- Manga and Webtoon Production
- 2D Frame-by-Frame Animation
- High-Resolution Print Production
PGM
Use PGM when…
- Computer Vision and Machine Learning Pre-processing
- Scientific and Medical Image Processing
- Unix/Linux Command-Line Image Pipelines