A quick guide to file formats
Different file formats are suitable for different purposes. Graphic elements such as logos may be made up of pixels or lines. The line-based formats are mainly used in professional graphics production, while the pixel-based formats can be used both professionally in images and at the office in programs such as Microsoft Word and PowerPoint.
Stands for Portable Digital Format, and this is precisely what it is: a file format which embeds layout and typography information so that you can be sure that all recipients will see the document in the same way. All you need to be able to read this file format is a PDF reader, e.g. Adobe Acrobat Reader or similar, which can be downloaded for free. A huge number of commercial programs have this read function built in, including most major established browsers.
PDF is primarily used as a distribution format for both on-screen display and printing. It is also a perfect option for proofreading, as there are plenty of options for commenting on the document or highlighting elements.
As PDF documents can be inserted in other documents, this may work as a more compact alternative to EPS documents. PDF has also become a preferred format for advertisements to be printed in newspapers.
Used for vector graphics. A line-based format which permits scalability. AI is preferable when you want to create paper-based printed matter or prints on clothing and signs. Stands for Adobe Illustrator.
Used for vector graphics (sometimes also for pixel graphics). A line-based format which permits scalability. EPS is preferable when you want to create paper-based printed matter or prints on clothing and signs. Stands for Encapsulated PostScript.
Used mainly for photographs and online. A pixel-based format. Stands for Joint Photographic Experts Group. Very effective compression, but with quality losses.
Used for graphics and photographs, as well as online. A pixel-based format. A PNG file can have a transparent background and be mounted in PowerPoint and Word with perfect results. Stands for Portable Network Graphics.
Indd stands for InDesign and is a program used to create layouts and printed matter, e.g. business cards, signs, brochures, etc. All of the above file formats can be mounted in InDesign, but a line-based format is preferable as this permits unlimited scalability.