Not all file types are created equal.
One of the first things I learnt when working in the office is that not everyone comes from a creative background.
I get asked a lot for things that seem simple, but what seems simple to me could mean nothing to someone else, and vice versa. I wouldn’t be able to add a formula to Dave’s spreadsheet so why should he know that PSD means Photoshop file. In the first of a series of posts I attempt to cover the most basic level of design knowledge to help all departments of the office, from finance to marketing to HR (super helpful for designers too, I had no idea about some of these). Confused about what file type you need? I’m here to help.
Raster images: These are pixel based graphics. They are resolution dependant, meaning the bigger/smaller you make them the more ‘pixelated’ they get. Raster images are typically used for photographs, and are edited in Adobe Photoshop (Photoshop files are marked as PSD).
Vector images: These are digital artwork files made out of points, lines and curves. Unlike raster images, vectors can be resized without losing any detail. Vector images are typically used for logos, icons and typefaces, and are edited in Adobe Illustrator (Illustrator files are marked as AI).
There are different types of both raster and vector images, used for different design scenarios.
Raster image file types
JPEG: pretty straight forward, JPEGs are photo files. They can be compressed to make the file size smaller, but this effects the quality and results in a more ‘pixelated’ image. They are best for online photos and print. They are limited when it comes to transparency, as they will always have a background.
PNG: the main thing to remember about PNGs is that they have the ability to be transparent, so the background can be removed. This is great for web graphics, as they can show 100s of colours. However, they are optimised for screen so won’t work well if it needs printing.
TIFF: these files are extremely high-res, typically used for photographs and scanned documents. They are directly editable, meaning they can be opened in Photoshop to access the layers of the image. They also allow for transparency.
Vector image file types
PDF: although PDF files can contain raster images, they work off of a vector graphics foundation. PDFs are universal and can retain detail no matter the device/application accessing them. Primerally, these are used for print, so any file that gets sent to the printers will be a PDF. It is also the file type of choice for any document, such as flyers/posters. Although PDFs are editable through Adobe Acrobat, they should mainly be used for a finalised design.
EPS: an EPS file retains all the benefits of a vector graphic, allowing it to be enlarged without out and loss of detail. Typically EPS files contain 1 design element, such as a logo, that can then later be placed into a full design. They focus on vectors, so shouldn’t be used for photographs (although photos can be put within them).
SVG: these are graphics designed specifically for the web. SVG files contain the code needed to recreate the vector graphic within a browser. They can be edited through Adobe Illustrator or by going into the actual code itself and changing it there. As a vector file, they can be enlarged without loss of detail, and as they are made from code can be animated easily.
