When it comes to images such as logos, photos or other graphics, the printing industry works with two types: vector and raster. As consumers who go about our daily business, these two types of art are all around us. Consider newspapers, magazines and food packaging today. They are all using one or the other or some combination of both types of art to communicate their messages to consumers. Whenever we see large, three dimensional signage on buildings or storefronts such as McDonald’s, Starbucks or Target, we are looking at artwork that started out as vector art. When you see product photos in catalogs or breathtaking photos in National Graphic, we are looking at raster art.
Vector art is ideal for printing since the art is made from a series of mathematical curves. Because of this, vector art images will print very crisply even when resized. As an example, a vector logo can be printed on a small sheet of copier paper and then be enlarged to billboard size without any loss of quality to the logo. The same logo as a low-resolution raster graphic would blur or pixelate excessively if it were enlarged from business card size to billboard size. The precise resolution of a raster graphic necessary for high-quality results depends on the viewing distance. Using the billboard as an example, a raster graphic may still appear to be of high quality even at low resolution if the viewing distance is great enough.
The opposite of vector art is raster art. Raster graphics are resolution dependent, meaning they cannot scale up to an arbitrary resolution without loss of quality. This property contrasts with the capabilities of vector graphics, which easily scale up to the quality of the device rendering them. Raster graphics usually work better for photographs and photo-realistic images. Vector images work best for typesetting and graphic design.
The gift voucher image below is based on vector art. There are clean, crisp fonts and shapes as well as gradients. All of this makes for art that can be
scaled to any size without any loss in quality. The image below it shows the curves and node points as they are seen when working with the artwork
in a vector art based program such as Adobe Illustrator.
The photo of the kids below is raster based. The detail of the image below (the eyes from the girl on the far right side) shows what happens when raster
art is enlarged too much. Notice how the photo now looks blurred.