If you’re running a contest for a logo or some other design which will be featured in print, you should ask for a CMYK image in either PDF, EPS, SVG, Corel Draw CDR, or Adobe Illustrator AI format. You may need to download a special program to view these files.

For website designs, Twitter backgrounds and other designs which are destined to be displayed only on computer screens, you should ask for a “layered RGB file” in Photoshop PSD or Fireworks PNG format. These are the source files of the design, and you’ll need them if you want to be able to easily tweak something. It’s a good idea to also ask for a JPEG version.

You shouldn’t ask the designers to provide any of the fonts used in the design, as many of them are owned by type foundries and carry hefty licence fees.