All Logos Files are Not Born Equal
After recently explaining yet again why the jpeg of a logo, taken from the website, can’t be used for a brochure, I thought it might be useful, valuable and insightful for someone to write this down. So here we are. Trying not to get all technical, I’m going to explain as clearly as I can, the difference between the different kinds of files. Hopefully this will save both clients and designers lots of time and heartache.
Different File Types
Most popular image files break down into two basic groups Bitmap or Vector.
A Bitmap image is resolution dependent. Which means it can only be used at the size it was created for or smaller. There are many types of bitmap files, JPEG, TIFF, PSD, PNG are all bitmap file types. Any digital photograph, for example, will be a bitmap image. They’ll use different techniques to store the information but are always defined by the resolution, that is a pixel by pixel count. Think of them as mosaics with each pixel being a tile. You make the mosaic bigger, you’re going to see the cracks.
A Vector image is resolution independent. Which means it can scale up to any size. There are many type of vector files, AI, EPS*, WMF, SVG are all vector files. The key thing is, no matter the format, they all use points in a XY space to mathematically describe the shapes in the image. No matter how much you scale it up, because it uses maths to describe the shape it’ll still be sharp. (*Just to confuse things an EPS or PDF file can contain a bitmap image)
To demonstrate the difference we’ll use the diagram above and scale it up a couple of hundred percent. If we use a bitmap file when scaled, we’ll start to see jaggy blocks, these are the pixels that make up the image (left blow). But if we use a vector format, no matter how large we go it uses the maths to create sharp edges and smooth curves (right below). There are also differences in the colour capabilities, but that’s another days discussion.
Different File Requirements
When using an image in print it needs to be at least 4 times the size (resolution) that it needs to be on screen. So if a brand mark is to be an inch high on screen it can be 72 pixels high, but for it to look sharp when printed it must be at least 300 pixels high – that’s because the printing process requires more detail in the file than a computer screen does.
This is where you get into real trouble when you try to use files created for websites (JPEGs) in print jobs. With vector files, it doesn’t matter, as they can scale to any size. EPS files, traditionally, are the most common vector file format that a logo would be created in, hence it is the one a designer will ask for when they would gladly accept any vector format.
We now supply logo artwork to our clients as vector PDF files and bitmap PNG files. This gives our clients to best of all possible worlds. Vector PDFs are basically modern EPS files they use the same vector technology and can be viewed freely with Acrobat. The PNG files are similar to JPEGs except they can have transparency and are great for Word or Powerpoint.
So there it is, the long and the short of why all files are not born equal. If you have any questions about this or if you’d like to know more about our logo design services or any of our ideas that make it easier for you to use your brand mark simply and effectively why not get in contact? We’re always happy to help.
Director of Design