File types… AKA: The mysterious world of design-tech acronyms that most of us have no clue what they mean or how the heck they’re used.
In a design studio, we run into situations with clients and vendors in which confusion about file types is a common conundrum. So we decided to offer up a simple guide to help explain some of the most common file types that you may run into in the world of business and design.
First, let’s talk about raster (pixels) file types vs. vector (paths) file types.
What’s the difference?
“The key difference between pixel and vector based graphics is how the image is structured. Pixel based graphics are made up from lots of tiny physical squares (or ‘pixels’) whereas vector graphics are mapped out using mathematical equations which calculate where the edges (or paths) of the shapes sit in relation to one another.”
Raster (Pixel) File Types: JPEG / PNG / TIFF
JPEG – Joint Photographic Experts Group
What it is: A pixel file that is “created by choosing from a range of compression qualities (actually, from one of a suite of compression algorithms).” In other words, a JPEG file takes the elements of an image and strips it of extra pixels that are not necessary to the visual quality of the image. This is why one of the most common internet image resolutions is 72 dpi (dots/pixels per square inch).
If you’re cruising the World Wide Web, you’re scanning hundreds of JPEG’s… perhaps thousands, if you’re conducting a Google image search. That’s because JPEG’s are the lowest resolution of the pixel file types, which makes them perfect for websites that you don’t want slowed down by large file sizes.
Common/Best Uses: website images / social media / photo sharing
PNG – Portable Network Graphics
What it is: “PNG format uses lossless compression and is generally considered the replacement to the GIF image format… [but] unlike GIF, PNG files do not support animations.”
When you see an image “free-floating” on a background, it’s likely to be a PNG. This is because PNG’s are the best file type when it comes to transparency. PNG files are formatted in such a way that the “transparent areas of the PNG will blend and adjust naturally to whatever is behind the image when the background of the page isn’t a solid white or black color.”
Common/Best Uses: website images on a background / product display images
TIFF – Tag Image File Format
What it is: “TIFF files are created in what is known as loss-less format—what you see is what you get. While larger in size, saving files in this format ensures that images will produce and maintain the highest quality for future use. TIFF images are also difficult to alter, making them ideal for protecting information and archiving.”
A TIFF is useful when it comes to archiving your digital images securely and at a high quality. Take note, when saving your TIFF files, be sure that you use a file name that’s easily searchable, as TIFF’s themselves are not searchable when it comes to text located in the file.
Common/Best Uses: archiving / base file for designers to start with
Vector (Path) Files Types: PDF / EPS / Ai
PDF – Portable Document Format
What it is: “A file format used to present and exchange documents reliably, independent of software, hardware, or operating system…PDFs can contain links and buttons, form fields, audio, video, and business logic. They can also be signed electronically and are easily viewed using free Acrobat Reader DC software.”
When it comes to the world of business, the PDF is perhaps the most prevalent of all file types. Its combination of versatility and compatibility make it a workhorse of information sharing. When it comes to determining whether to save as a TIFF or PDF, unless you’re saving some type of master file, you’ll most often want to go with PDF, due to its smaller file size and superior compatibility attributes.
Common/Best Uses: marketing materials / business documents / design briefs
EPS – Encapsulated Postscript
What it is: “An EPS file internally contains a description of such an object or layout using the PostScript page description language. It can include both bitmap and vector data. The purpose of an EPS file is to be included in other pages.”
The humble EPS is considered the predecessor to the PDF, though it does have slight differences, both in format and purpose. The people still using EPS are mostly designers and printers, and even then, they are most likely in the minority when compared to the majority who prefer press-ready PDF’s.
Common/Best Uses: backup file / still used by some printers / master graphics files
Ai – Adobe Illustrator
What it is: “The .ai file type is the rawest of raw. It’s the file containing the original lines in a controllable and modifiable format in various layers. From this center point, all of the other file types are exported.”
Seeing as how this is the file format that is most likely to be incompatible for the average person to open, it’s important for people on the business or marketing side of things to be able to recognize this file type and, if needed, request an alternate file format such as a PDF.
Common/Best Uses: original file / working file / sharing between designers