Why the logo you got off a website will not work for print
(or, the difference between vector and bitmap images)
Working in the design and print industries since the early internet era, one problem I’ve had to deal with over and over is this: people want to use the logo they’ve pulled off a website for a printed brochure, ad, or (yikes) blow it up large for a poster or billboard. They send their designer the logo and are surprised when either the printed logo looks terrible, or their designer rejects the file outright.
It seems logical; the logo looks great on screen! Why can’t it be used for print? The answer lies in two words: vector and bitmap.
Graphics of all kinds basically fit into one of these two categories. Photos are bitmap images. This means they are made of many little units, called pixels. When you zoom into a bitmap (also called raster) image, or enlarge it a lot, you can see the pixels.
In order for a bitmap image to look good when it’s printed on paper, it has to have a lot more pixels per inch (PPI) than an image that’s just for viewing on a screen. Most screens — computer monitors, TVs, mobile devices — don’t need more than 96 pixels per inch for an image to look good.
But for an image to look good on paper, you need many more pixels per inch. Most offset presses (the kind you’d use for magazines, brochures, and other items printed in large batches) need images that are at least 250 to 300 ppi for good results.
Digital printers can provide pretty good results with fewer pixels per inch, but it’s a good idea to keep images above 200 ppi.
Even an image that has enough pixels per inch to look good at one size will look much worse if it has to get larger: when you make an image bigger, the pixels themselves get bigger. If you take an image that is 300 ppi and make it twice the size, it now has half the number of pixels per inch, because each pixel is twice as big. That leads to “bitmappy” looking images.
And when that image is a logo, or other design with sharp edges, the results are even more noticeable.
This type would look awful in print, right? At least, unless you’re going for that pixellated look.
So what’s the solution?
Vector images. Logos and line art that have been created in a vector program are not made of individual pixels. They’re actually mathematically-created sets of points and lines.
Each line in a vector file is made of points with lines between them. Each point has handles that control the curve.
Because it’s all done with numbers, a vector image can be made as large as you want — even big enough to make a banner for the side of a building — without losing resolution.
A good designer creates all their logos in a vector program. They know that if they use a bitmap editing program to create a logo, they’re stuck with it at that size — there’s no way to add pixels accurately. What if the client wants the logo used at a larger size? They’re out of luck.
And the logos you find online are pretty much always in a bitmap format. How can you tell? Usually you can tell by the file extension. If it’s .jpg or .gif that is a bitmap file. Vector files typically have the extensions .eps or .ai.
It can sometimes be hard to track down the vector version of a logo, but it will definitely be worth your time, and you’ll end up with much nicer results. Your printed piece will look good, and you’ll look good.