Image MIME Reference
DWG
AutoCAD Drawing
image/vnd.dwg
VS
MacPaint Image
image/x-macpaint
MacPaint
A complete technical comparison of AutoCAD Drawing and MacPaint Image — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.
Equal browser support
Feature Support
| Feature | DWG | MacPaint |
|---|---|---|
| Transparency (Alpha) | Yes | ✕ No |
| Animation Support | ✕ No | ✕ No |
| Progressive Loading | ✕ No | ✕ No |
| HDR Support | ✕ No | ✕ No |
| EXIF Metadata | ✕ No | ✕ No |
| ICC Color Profile | ✕ No | ✕ No |
AutoCAD Drawing
image/vnd.dwg
Extension
.dwg
Container
DWG Binary Container
Compression
Proprietary Binary Compression (LZ77 based in newer versions)
Algorithm
Proprietary (Autodesk ObjectDBX)
Color Depth
Vector (True Color / Indexed AutoCAD Color Index)
Developed by
Autodesk
Released
1982
Magic Bytes
41 43 31 30 (AC10)
MacPaint Image
image/x-macpaint
Extension
.mac.pntg.pnt.macp
Container
Raw pixel payload with a 512-byte pattern header
Compression
PackBits (Run-Length Encoding)
Algorithm
PackBits (Apple RLE)
Color Depth
1-bit (Monochrome)
Developed by
Apple Computer, Inc. (Bill Atkinson)
Released
1984
Magic Bytes
None (Relies on classic Mac OS 'PNTG' OSType)
Browser Support Comparison
| Browser | DWG | MacPaint |
|---|---|---|
Chrome
|
✕ | ✕ |
Firefox
|
✕ | ✕ |
Safari
|
✕ | ✕ |
Edge
|
✕ | ✕ |
IE (Legacy)
|
✕ | ✕ |
DWG
DWG Strengths
- The undisputed industry standard for 2D drafting and basic 3D CAD modeling
- Highly optimized binary structure keeps file sizes relatively small compared to text-based CAD formats like DXF
- Supports incredibly complex datasets including external references (XREFs), dynamic blocks, and extensive custom metadata
Limitations
- It is a closed, proprietary format, making it difficult for third-party developers to support fully without licensing the Open Design Alliance (ODA) SDK
- Lacks native web or standard operating system previewer support
- Format versions change frequently (roughly every 3 years), breaking backward compatibility for older CAD software
MacPaint
MacPaint Strengths
- Profoundly historically significant as the format that introduced millions to the concept of bitmap digital painting
- Extremely simple PackBits compression makes it easy for emulator developers or archivists to write parsers from scratch in under an hour
Limitations
- Severely limited: strictly black and white, and hard-locked to exactly 576 x 720 pixels
- Lack of standard magic bytes makes programmatic file sniffing unreliable on modern filesystems without relying on the file extension
- Completely obsolete and unsupported by modern web browsers or consumer image viewers
When to choose which format
DWG
Use DWG when…
- Architectural Floor Plans
- Mechanical Engineering Models
- Civil Engineering Drafts
- 3D Product Designs
MacPaint
Use MacPaint when…
- Historical Apple Macintosh Archival
- Early 1980s Digital Art Preservation
- Retro UI/UX Academic Research