Vector vs. Bitmap or Raster Graphics
What are Vector and Bitmap artwork, and what is the difference. Most popular graphic design programs are usually one or the other, and sometimes even both. In essence, vector graphics use mathematical points and curves to create scaleable imagery without any loss in quality. For example, a line you draw on the screen is in fact saved as a set of instructions for shape and length, which can be scaled up or down to any size.
On the other hand, raster artwork (also called bitmap) is a pixel-based collection of color information. This means that drawing a line on the screen is a collection of pixels, which may not scale very well. All photographs are raster-based, which is why it is so very important to use high-resolution pictures in your artwork!
Graphics are used in print for 2-D text, logos, illustrations, and even 3-D animations for web and screen. When vector graphics and text are used for most print processes, there is a clean edge and very fine lines. Some print processes like silkscreen disc printing require vector images set up in spot colors like Pantone Matching System (PMS) colors. Since silkscreen printing pushes ink through a fine screen, the vector image when applied in a PMS spot colors does not show a “dot pattern” from the screen, since it does not have other halftones of color makeup being applied on it. This creates a truly solid color. Vector text has the clean edges that make even the smallest text more legible, when used with print processes such as PhotoPro printing or Offset disc printing.
Photographs are the easiest thing to think of when referring to Raster or bitmap artwork. Raster graphics are made up of individual pixels where each contains specific color information, where the total number of pixels (resolution) and the amount of detail in each pixel determine the quality of the raster graphic. For best print quality, using images that are 300 pixels per inch are best, but even as low as 150 pixels per inch may print with a decent quality.
One of the most important things to understand about Raster graphics is that they are resolution dependent. This means that they have a loss in quality when resizing to a larger scale, where vector images can scale larger with no loss in quality. Raster programs (such as Adobe Photoshop or Corel Paint Shop Pro) are best for photo editing and retouching full-color graphic images. Using raster-based programs to layout text can turn your text into pixel based graphics, which will make your text print with a slight blur in some print processes. PhotoPro and Offset disc printing are recommended when using raster graphics to retain the detail and quality of the photographic images.
Our advice is to use vector text and graphical elements whenever possible. Vector text looks very sharp with most print processes including silkscreen, Offset, and PhotoPro printing. When using photos in your artwork, use high-resolution images and select a print process (such as PhotoPro or Offset) that is well suited to raster graphics.