When examining printed collateral that features low resolution raster imagery, it rarely takes a trained eye to see how pixelated the resulting imagery is. While there are numerous reasons for the pixelated effect -- such as a designer being provided with low resolution images -- what’s important is the blemish that it will impart on the final product. No matter how great your design may be, pixelation can detract from the quality of the design and give the product an amateurish look. But if you know how you want the finished, printed design to look, why is it so difficult to decide which one to use?

One of the most significant differences between the two is that raster images are more limited than vector images. While the resolution of a raster image cannot be altered, vectors are not subject to a single specific resolution. Vectors are the result of math, and because they aren’t bitmapped, they can be changed to an infinite range of resolutions without the added worry of losing design quality. There is a problem, though: vector images are not always the right answer to every question. So when do you use vector, and when do you defer to raster?

There are some occasions where you won’t need to even consider using raster, such as when working with logos and type. You should also use vector when working with packaging, as packaging generally features logos and text more generously than photography. When you’re working with photography, you should always use raster images. High resolution is key here: never print anything below 140 DPI, and always aim for 300 DPI and above. If your vector vs. raster concern hinges on photo quality, now is not the time to lose focus on that. In general, you will need to use a combination of both for print work, so it’s crucial that you and your designers are able to understand which one should be used in any situation.

To ensure that their products look flawless, many technology companies have made use of vector images of photorealistic artwork rather than actual product photos. Although this may be a very useful option, it requires a fairly simple product design and a high level of skill with Illustrator or another vector-based graphics program. The vector image must be incredibly detailed in order to perfectly mimic the original product, or else consumers may notice the difference. Use vectors when possible instead of photos, but do so with discretion.

Knowing when to use vector and raster images is absolutely critical to creating the highest quality printed collateral. By keeping in mind these simple distinctions, you’ll be well-equipped to decide which image type to use and when.

Graphic Dimensions offers a full service prepress and graphic design department (LaunchPad Division) that can help answer any of your design and file format questions.