What's the Difference Between Raster and Vector Graphics?
When it comes to digital graphics, you may have come across the terms "raster" and "vector." Understanding the difference between these two types of graphics is essential when setting up graphics files for print.
Raster Graphics
Raster graphics are composed of pixels. Each pixel is assigned a specific color and placed in a fixed position. When you zoom in on a raster image, you'll notice that it's made up of tiny squares, each representing a pixel. Common file formats for raster graphics include JPEG, PNG, and GIF.
The primary characteristic of raster graphics is that the quality and clarity of the image are determined by the number of pixels per inch (PPI) or dots per inch (DPI). Basically, that means that the larger it's resized the more pixelated it will become. For example, if a raster file is created at 2"x2" and blown up to 20"x20", it will look pixelated.
Raster graphics are perfect for photographs and detailed illustrations. They can capture subtle color gradients, textures, and intricate details.
Vector Graphics
Vector graphics are composed of points, lines, curves, and polygons to create images. They can be scaled infinitely without any loss of quality. For example, if a vector file is created at 2"x2" and blown up to 20"x20", it will look perfect. In fact, it could be blown up to literally any size and not lose quality. Common file formats for vector graphics include AI, EPS, PDF, and SVG. However, not all of these formats mean the graphics in them are vector. A JPEG can be saved as an AI but that doesn't make it a vector file.
Another bonus to vector files is editability. Individual parts of the file can be deleted, moved, changed color, etc.
They are most suitable for stylized illustrations. Due to their mathematical nature, vector graphics struggle to capture intricate details, textures, and subtle color gradients found in photographs but there are definitely some vector artists that can create vector art to look like photographs.
What if I have a raster file and need it in vector?
First you'll need a vector graphics-based software program such as Adobe Illustrator. (Not Photoshop; that is for raster files.) What we do is import the file into Illustrator then manually redraw the graphics using the tools in Illustrator. This can be a time-consuming process which is why we need to charge to do that but it yields the best results. There is also as "Image Trace" button in Illustrator that does a pretty decent job on 1 or 2 color, high resolution raster files but the quality on complex files (especially ones containing text) will suffer.