Free webp to jpg
Image MIME Reference
PWG-Raster

PWG Raster Format

image/pwg-raster
VS

AutoCAD Slide

image/vnd.sld
SLD

A complete technical comparison of PWG Raster Format and AutoCAD Slide — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature PWG-Raster SLD
Transparency (Alpha) ✕ No ✕ No
Animation Support ✕ No ✕ No
Progressive Loading ✕ No ✕ No
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No ✕ No
ICC Color Profile ✕ No ✕ No
PWG Raster Format
image/pwg-raster
Extension
.pwg.ras
Container CUPS Raster v2 Container
Compression PackBits (Run-Length Encoding)
Algorithm
PackBits (Apple RLE variant)
Color Depth 1-bit (Monochrome/K), 8-bit (Grayscale), 24-bit (sRGB / Adobe RGB), 32-bit (CMYK)
Developed by IEEE-ISTO Printer Working Group (PWG)
Released 2011
Magic Bytes
52 61 53 32
Full PWG-Raster reference →
AutoCAD Slide
image/vnd.sld
Extension
.sld
Container AutoCAD Slide Container
Compression Uncompressed (Vector Instructions)
Algorithm
None
Color Depth 8-bit (AutoCAD Indexed Color)
Developed by Autodesk, Inc.
Released 1980s
Magic Bytes
41 75 74 6F 43 41 44 20 53 6C 69 64 65 0D 0A 1A 00
Full SLD reference →

Browser Support Comparison

Browser PWG-Raster SLD
Chrome Chrome
Firefox Firefox
Safari Safari
Edge Edge
IE IE (Legacy)
PWG-Raster

PWG-Raster Strengths

  • The undisputed global standard for modern, driverless printing environments, eliminating the nightmare of installing manufacturer-specific print drivers
  • Extremely lightweight to decode on embedded hardware, requiring minimal RAM buffers on the printer side
  • Strict color space and resolution rules guarantee that the printed output will successfully process without syntax errors
Limitations
  • Generates massive file sizes and network payloads compared to vector-based formats like PDF or PostScript, as every page is fully rasterized at 300+ DPI before transmission
  • No support for native rendering in web browsers, image viewers, or graphic design software without specialized CUPS developer tools
  • Cannot store complex metadata, vector text, or layers
SLD

SLD Strengths

  • Allowed for instantaneous loading of highly complex architectural and engineering blueprints on low-memory MS-DOS systems
  • Easy-to-parse binary structure containing simple opcodes for drawing vectors and polygons
Limitations
  • Completely obsolete and heavily fragmented, largely replaced by PDF and lightweight web-based DXF viewers
  • Destructive 'snapshot' format irrevocably strips all useful, editable CAD geometry data from the original drawing
  • Zero support in web browsers or standard image processing libraries

When to choose which format

PWG-Raster
Use PWG-Raster when…
  • Driverless Network Printing (IPP Everywhere)
  • Apple AirPrint and Mopria Print Service Pipelines
  • CUPS (Common UNIX Printing System) Spooling
SLD
Use SLD when…
  • Legacy AutoCAD Slideshows
  • AutoCAD Custom Icon Menus
  • Historical CAD Archival
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