20 Aug Vector vs. Raster – The Differences + How to Get a Crisp Print
Many questions are raised during the beginning stages of a design project, and the choice between Raster and Vector is one of the most important. The answer lies in your final plans for the design and the artwork, but we find it’s best to start by understanding the difference between the two file formats.
Vector images are made up of basic geometric shapes such as points, curves, and lines. A mathematical equation is used to determine the relationship of the shapes and allows you to scale the shape up or down in size without losing quality. Vectors are great for logos, illustrations, and other designs without gradients or photographic images. Vectors also have the advantage of a much smaller file size, making them easier and faster to work on.
If the image is increased in size, the equation is recalculated resulting in a larger design with no loss of data or detail. As a result, resolution (the quality of the image at different sizes) is not an issue with vector graphics.
Popular vector drawing software Adobe Illustrator, Corel Draw or Inkscape can all create vector designs suitable for screen printing.
Clean vector graphics are the key to crisp and detailed prints.
Raster images are made up of a grid of pixels, where each pixel is assigned its own individual colour value. Typically the number of pixels in an image is in the millions. When a raster image is enlarged, the grid of pixels is stretched. This can cause all sort of quality loss, including jagged edges around text and other shapes.
The term ‘dpi’ refers to ‘dots per inch’. Raster images intended for print are usually from 300-600pi, whereas low quality web images are optimized to 72dpi. Raster images must be created in the size the image is intended to be used. Any stretching at all causes massive quality loss.
Editing software like Adobe Photoshop, and GIMP are the most popular for altering and creating raster images.
Popular raster file include: .JPG/.JPEG, .PSD, .PNG, .TIFF, .BMP, and .GIF.
Most designs are suitable for vector format, and vector designs are the easiest way to ensure crisp print.