Digital graphics are generally divided into two major types: raster graphics and vector graphics. These systems represent visual information differently and are used for different purposes in design and fabrication workflows.
Understanding the difference is important in CNC Routing, Laser Cutting, CAD, illustration, and digital manufacturing.
What Are Raster Graphics?
Raster graphics represent images using a grid of pixels.
Each pixel stores color information, forming a complete image.
Common raster formats include:
- JPG
- PNG
- BMP
- TIFF
Raster images are commonly used for photography and detailed textures.
Characteristics of Raster Graphics
Raster images:
- are resolution-dependent
- lose quality when enlarged
- contain pixel-based detail
- work well for complex images and photos
Higher resolution means more pixels and more detail.
What Are Vector Graphics?
Vector graphics represent geometry mathematically using:
- points
- lines
- curves
- paths
Common vector formats include:
Vector geometry can scale without losing quality.
Characteristics of Vector Graphics
Vector graphics:
- scale infinitely
- remain sharp at any size
- support editable geometry
- work well for fabrication and technical design
This makes vector systems ideal for CNC workflows.
Raster vs Vector Comparison
| Raster Graphics | Vector Graphics |
|---|---|
| Pixel-based | Geometry-based |
| Resolution-dependent | Resolution-independent |
| Best for photos | Best for technical geometry |
| Difficult to edit precisely | Easily editable |
| Large files at high resolution | Often lightweight |
| Limited scaling quality | Infinite scaling quality |
Both systems are useful for different applications.
CNC and Fabrication Workflows
Most CNC systems require vector geometry because machines follow mathematical paths during machining.
Vector files are commonly used for:
- cutting
- engraving
- routing
- toolpath generation
Raster graphics usually cannot be machined directly without conversion.
Laser Engraving and Raster Images
Some fabrication workflows intentionally use raster images.
Examples include:
- laser engraving photographs
- texture engraving
- grayscale burning
- image etching
These operations interpret pixel brightness instead of vector paths.
CAD and Engineering Workflows
CAD systems primarily use vector geometry because engineering and manufacturing require precise dimensions and editable geometry.
Vector workflows support:
- dimensional accuracy
- scalable production
- precise toolpaths
- manufacturing repeatability
Raster graphics are generally unsuitable for technical fabrication geometry.
File Conversion
Raster and vector files can sometimes be converted.
Raster to Vector
Processes include:
- tracing
- edge detection
- vectorization
Results may require manual cleanup.
Vector to Raster
Often used for:
- previews
- rendering
- image export
- web graphics
Conversion reduces editability and scalability.
Common Problems
Typical raster issues include:
- blurry scaling
- pixelation
- low resolution
Typical vector issues include:
- broken curves
- unsupported splines
- geometry complexity
Each workflow has different technical limitations.
Choosing the Right Format
| Goal | Preferred format |
|---|---|
| Photography | Raster |
| CNC machining | Vector |
| Technical drafting | Vector |
| Texture artwork | Raster |
| Laser engraving photos | Raster |
| Precision fabrication | Vector |
The correct format depends on the intended workflow.