Vector vs. Raster Graphics

05 Jan Vector vs. Raster Graphics

Have you ever downloaded a picture from the internet to print out onto paper, only to find that the graphic is all fuzzy and pixelated? You’re not the first, and definitely not the last! This is a real struggle that many of us have faced while printing out documents in the office, or working with a printing company that just can’t seem to get our graphics to work.

Arrggg – the frustration!! Let’s take a deeper look at why this happens.

There are 2 main graphics formats that the design industry uses: vector and raster. Let’s discuss the differences between these two in order to understand how and when to use each one.

A vector graphic is built using mathematical equations to create objects. These objects can be scaled to any size needed, whether it is smaller or larger than the original object. This means that you can create a design at a small size – let’s say 2 inches by 2 inches – and then, you can take that same design and make it 4 feet by 4 feet, without any of the image getting blurry, fuzzy, or pixelated. The other benefit to a vector graphic is, because of the fact it is created with mathematics, it is usually a relatively smaller file size than a bitmap image.

On the other hand, a raster image is created with hundreds or thousands of tiny dots, called pixels. A pixel cannot be made larger than its original size without breaking up and getting fuzzy. When a raster image is expanded beyond it’s original size, it can become “pixelated” and start to lose quality. Because a raster image is created with many pixels of many different colors, it usually creates a relatively larger file size.

So, now the question is “How do I know the difference between the two of them?” Here is a quick and easy solution for this. Look at the file extension name – the name after the period, such as filename.jpg. A vector graphic, usually built using Adobe Illustrator, will end with a .eps, .svg, or .ai, while a raster image (which can be created by a number of design programs) will end with .bmp, .jpg, .gif, .tiff, or .png.

One other term to make note of is this: when a designer or printing company is asking for a high-resolution image, they are usually requesting a vector image. If a vector image is not available, then a raster image will work as long as the size of the image is large enough to meet the final project’s needs without becoming pixelated. Most, if not all, printing companies require that all raster images be at least 300 dpi or larger.

“What is DPI?” you ask? That is for another day and another article!