The difference between raster and vector files and when you should use them

Using vector files

A vector file can be created in applications like Adobe Illustrator or CorelDAW and are primarily used for graphics or illustrations such as logos etc.

A vector file is list of coordinates for a series of paths with a start point and an end point, paths are combined to make range of objects/shapes. These paths are saved as a mathematical algorithm.

The advantage of a vector image is that it can be resized infinitively without losing quality. The vector algorithm will render the image when it is resized.

Vector files are also used to add cut contours to artwork for heat transfer vinyl or sign vinyl.

Working with raster images

A raster file can be created and manipulated in an application like Photoshop and are primarily used for photographic images.

A raster image is rectangular grid of dots (pixels) and each dot has a fill colour, together they make the image.

The pixels are independent and do not have any correlation with each other i.e. the software only knows it as red, black and grey dots next to each other and not as a picture of a rose.

A limitation of a raster file is resizing; when increasing the size, it will become blurry (pixelated). This is because the pixels are becoming larger or the software is adding extra pixels into the image and these pixels may be the wrong colour.

All raster files have a resolution and generally speaking; the higher the resolution the higher the quality of the image.

An in-depth explanation of raster and vector files is covered in our GJS Printing Courses.