Image MIME Reference
CLIP
Clip Studio Paint Document
image/vnd.clip
VS
JPEG 2000 Image Sequence (Obsolete)
image/hsj2
HSJ2
A complete technical comparison of Clip Studio Paint Document and JPEG 2000 Image Sequence (Obsolete) — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | CLIP | HSJ2 |
|---|---|---|
| Transparency (Alpha) | Yes | Yes |
| Animation Support | Yes | Yes |
| Progressive Loading | ✕ No | Yes |
| HDR Support | ✕ No | Yes |
| EXIF Metadata | ✕ No | Yes |
| ICC Color Profile | Yes | Yes |
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
JPEG 2000 Image Sequence (Obsolete)
image/hsj2
Extension
.hsj2
Container
HEIF / ISOBMFF (ISO/IEC 15444-16 Obsolete)
Compression
Lossy / Lossless
Algorithm
Motion JPEG 2000 (ISO/IEC 15444-3)
Color Depth
8-bit, 10-bit, 12-bit, 16-bit
Developed by
ISO/IEC JTC 1 / ITU-T
Released
2019
Magic Bytes
XX XX XX XX 66 74 79 70 68 73 6A 32
Browser Support Comparison
| Browser | CLIP | HSJ2 |
|---|---|---|
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
HSJ2
HSJ2 Strengths
- Historically attempted to combine Motion JPEG 2000 sequences with the flexible metadata capabilities of the HEIF container
- Supported mathematically lossless compression and scalable wavelet decoding
Limitations
- Officially deprecated by the standardization body (ISO/IEC JTC 1)
- Completely superseded by image/hej2k, rendering hsj2 files obsolete for any new development or archiving
- Zero web browser compatibility and negligible modern software support
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
HSJ2
Use HSJ2 when…
- Legacy Archival
- Deprecated Workflows