In a digital age, computer literacy is darn near as important as reading and writing. In an information age, knowing the file formats that are used to create the documents we see should be right up there with knowing your ABCs. Any more, if you plan to create communication documents, you should be aware of what different software programs do and what the files they create are useful for.
In case you’re completely (or even relatively) new at this, a brief explanation is necessary. All computer programs (like Microsoft Word or Adobe Photoshop) have file formats. When you create, say, a report in MS Word, you save the document by giving it a file name. At the end of that file name is it’s file extension. In MS Word, the extension assigned is .docx. PowerPoint is .ppt. Likely, you’ve seen this before and it is second nature to most people.
In the world of visual communication, a whole host of other file formats are critical to know. More than likely, you’ve used most of the ones I list below, but if you don’t know the difference between each of them, you won’t know how to get better at them. It’s kind of like grammar. You can communicate without knowing how to use a semicolon; once you learn, though, your writing becomes much stronger. You can create visual documents without understanding file extensions, too. But once you know the value of an .ai file over a .jpg file, you can do so much more.
So, with that in mind, here are the 10 file formats you must absolutely know if you want to be visually literate (listed in order of most important to least important):
PDF (said as an acronym, “P-D-F”)
The most important file type you should be aware of is PDF (“Portable Document Format”). PDFs are valuable because they have the unique ability to open on any computer and they keep the integrity of the original document. If you create a poster using a really cool font, for example, on your home computer and want to send it to a printer, chances are that printer doesn’t have the same font as you. All your hard work will be lost if you rely on copy centers to make your documents look the same on their computer as it does on yours. If you use PDF files, though, your font will remain in tact, no matter what computer. If you create a document in Illustrator, Photoshop, InDesign, or even Microsoft Word, it is good practice to save the file as a PDF so that it can be transferred to other computers without losing quality or characteristics (like fonts, layouts, and colors). PDFs retain the resolution integrity created in Photoshop and other programs. Because of their versatility, many printers and copy centers require that you convert your print projects to a PDF file before printing.
JPG (.jpg or .jpeg, pronounced “jay-peg”)
JPG are the next most recognizable file type and important to understand. JPG files have become the most common file types for images. JPGs are popular because they are able to compress file sizes at different levels, making them ideal for saving pictures where storage space is limited (on cell phones, digital cameras, and even on the Web). However, JPG files are considered a “lossy” file type because in the compression of the image, quality is lost. If you use a JPG file for a print document, be sure that it is a high resolution (at least 300 pixels per inch) with as little compression as possible. JPG files can also be opened on virtually any computer.
PNG (pronounced “ping”)
PNG files are considered a “lossless” file format—they don’t lose quality with compression. They are popular because their file sizes tend to be smaller than other lossless formats (like a TIF) when compressed. They are especially useful in visual communication and design because they have the capability of saving transparent backgrounds. What this means is, if you create an image using design software that isn’t rectangle in shape (like if you cut out the silhouette of a person), no background shape will be saved. In most other file types, a rectangular white shape will save behind the image. PNG files work well for both digital and print publications.
TIF (pronounced “Tiff”)
TIF files are considered the highest quality lossless (does not lose quality when compressed) file format for print. However, they also carry with them the largest file size, so storage and processing speed can be a problem with them. In most cases, you would not want to work with TIF files when creating something for the Web. If you are creating a large document with a lot of images and graphics (something like a textbook) and you use all TIF files, you might find your computer slowing down. But if you have a computer with a good processor and a lot of storage space, these are excellent file types for print publications because you won’t have the fear of losing any resolution.
GIF (usually pronounced with a hard “g” as in “golf”; however, the developer apparently meant for the file to be pronounced “jif”)
GIF files are becoming outdated (the PNG file is its replacement) because it had patented compression. However, you may still come across these file types because they can be compressed smaller than a PNG file, which can be good for fast processing on the Web. Usually, though, PNG files are fine. GIFs also have the ability save moving images and were really popular for smiling emoticons in the 1990s. Nowadays, though, animations like that are usually Flash objects. You won’t want to use GIF files for print.
AI (said as an acronym, “A-I”)
AI (.ai) files are proprietary files created in Adobe Illustrator. These files are best known for functioning as vector graphics, which means they are built from mathematical algorithms instead of pixels. The value in creating an image from math is that the file sizes are smaller and they can be resized without losing any resolution or quality. AI files are particularly useful for logos and line drawings because they can be blown up to any size (if you need to put your logo on a billboard, you’ll need to create your logo in an AI file). AI files are usually used for more iconic designs and simpler graphics like cartoons; they do not typically work well with photographs, though technology is getting close to making photographs vector graphics.
PSD (said as an acronym, “P-S-D”)
PSD files are proprietary files created in Adobe Photoshop. These files allow for layers to be created on top of images and are used for editing images and creating special effects. PSD files do transfer into InDesign, but it is common practice to convert PSD files to TIF, PNG, or JPG files before placing them into InDesign.
INDD (usually just referred to as “an InDesign file”)
INDD files are proprietary files created in Adobe InDesign. When working on print projects, you will want to save your INDD files so that you can edit them at any time. When you complete an InDesign project, however, you will usually end up exporting the file as a PDF.
RAW (pronounced just like the word)
Camera RAW files have been nicknamed “digital negatives” because they function much in the same way as film photography natives—that is, they can’t really be used or viewed as images until they are processed. Raw image files are typically taken with high-end cameras and can have precise adjustments made to the image before it is processed and ready for editing in computer programs and for print.