Whatâ€™s a vector and why do we need one?
on August 31, 2012 in best practices
What’s a vector and why do we need one?
So, you’ve hired a designer to make your website, flyer, brochure or novelty dog bib (a surprising percentage of our business) and now they’re asking for a vector version of your logo. What in the heck does that mean? You already sent them the jpg, so what more could they possibly want?! Well, here’s an explanation:
VECTOR vs. RASTER
Every digital image falls into one of two categories: a vector image, and a raster image. A raster image is made up of tiny dots called pixels that from far away (or zoomed out) looks like something. Any digital photograph, for example, looks like the thing it’s a photo of, but if you zoom in as far as possible, it is just a series of colored squares – kind of like a mosaic, or a Seurat painting, or an extremely coordinated crowd at a football game.
While a raster image is made up of individual pixels, a vector image is made up of lines. Vector images are made up of mathematically-defined geometric shapes: lines, filled areas, curves, etc. Each element of the vector has a mathematical set of rules, so when you scale it, the equation is merely recalculated at the current size. For this reason, vector images are flexible at any scale.
Notice that no quality is lost when we zoom into the image. This is because it’s made up of shapes, not pixels. Check out the image below. With vector handles shown, you can see how the image is put together. Think of it as color and form draped over a scalable wireframe skeleton. Like an architectural blueprint, or a color by numbers, or some big, weird, wiry giant skeleton that is crushing buildings, but it only wants to be understand love.
So, which one is better?
That all depends on what you need to do. Raster images are better when things need to be photorealistic. Because every section is made up of hundreds of pixels, you get a greater level of detail. Rasters images also handle complicated photo effects better than vectors. On the other hand, a vector is infinitely scalable so you can use the same image on anything from a button to a billboard. Since a smaller amount of information is being saved (basically just the formula for how to create the image) vector file sizes are usually much smaller than their raster counterparts. Most importantly, it is very easy to turn a vector image into a raster image; but nearly impossible to turn a raster image into a vector.
Why we need a vector image?
If a designer has asked you for a vector image, it’s probably because they need something scalable. Most often, they’ll need your logo as a vector. Even if you have a large jpg of your logo, it’s necessary to have a vector that can be scaled to any size. Print jobs are done at a minimum of 300 dpi, which means a 300 pixel wide jpg is only going to be an inch wide. Higher end print jobs are done at 450 or 600 dpi, meaning your 300 pixel jpg might only be half an inch wide, and if it’s not a vector, scaling it larger will result in a pixelated image and an overall decrease in quality.
How do I know which one I have?
Worst case scenario, your designer can tell you. But if you want to be a sweetheart and help them out, here’s a handy guide to file extensions.
DEFINITELY NOT A VECTOR
.jpg, .png, .tiff, .gif, .bmp, .exif
COULD BE A VECTOR
PROBABLY A VECTOR
.eps, .ai, .cdr
Why are .eps, .ai and .cdr files only probably a vector? Well, 99% of the time a file saved as an eps or ai file is a vector. However, occasionally people will just paste a .jpg into Illustrator and save it as an eps or ai file. This helps no one. Most likely this was done by somebody who does not understand the difference between raster and vector images and was told their designer needed something that ended with one of those file extensions. Sending this type of file to your designer is a good way to make them write a politely worded email to you that disguises the fact they are tearing their hair out. Just kidding, we never tear our hair out over our clients.
What if I absolutely don’t have a vector of my logo?
Chances are you do. If possible, get in touch with the person or company that originally designed your logo. Most likely a vector version exists and has been lost in the shuffle. If you’re a big enough company, a vector of your logo might even be available to the public on BrandsOfTheWorld.com or similar sites. If not, your logo was either designed in the early 90s, or you were bamboozled. Worst case scenario, send the raster version of your logo over, and a good designer can recreate it as a vector. Even with a simple logo, however, this can be time consuming, so expect to pay a little extra.