What the heck is an .eps file?

When working with a Graphic Designer, there comes a time where the final art files are delivered to you, and you can begin the exciting process of planning what you’d like to do with them, be it for a vinyl wall decal or in an email signature. Knowing which file type should be used for each of these kinds of projects can be confusing – should you choose a .png or .ai? …and what the heck is an .eps file?

These questions can often pop up when a branding folder full of logos using different file formats is handed over to you, and as with most things, clear communication is key to getting the most from your designer and saving time and money. Rather than a flurry of emails explaining what type of file to use and where, it helps to understand the basics of file types and to know exactly what you want out of the final product and which files you need to get it done.

Here is a guide to some of the different file types used by Project House Graphic Designers on a daily basis to help our clients make the most of their graphic projects. We’re going to start today with raster and vector based files, because this is the major differentiator of file types.

Raster Files

Raster files are made from pixels. If you expand a raster image, you will be able to see that the image is really made up of millions of tiny coloured squares that create the picture, similar to a mosaic effect.

Raster File Features

  • Raster images are fantastic at capturing realistic detail and are used for photography, photo editing, and digital painting.
  • Almost any digital program will recognize raster files and can work with them.
  • Raster files are resolution dependant. This means that increasing the size of a raster image spreads the pixels over a larger area and causes the loss of detail and clarity, which can cause big problems with print material, as expanded raster images can show up blurry and pixelated in the final product.

Common Raster File Formats Used at Project House

  • Joint Photographics Expert Group (.jpeg or .jpg): Jpeg’s are good for use in printing or digital media. They do not allow for transparency (meaning you can only use your design file on a white background).
  • Portable Network Graphic (.png): Png’s are good for use in digital media. This file type allows for transparency (meaning you can use the design file on a background of any colour).
  • Tag Interleave Format (.tiff): Good for use in printing, this file type allows for transparency.
  • Adobe PhotoShop (.psd): Great for editing raster images, psd’s are the main file type Project House uses for editing photographs. This file type allows for transparency.

Vector Files

Vectors are made out of nodes that have a set x-axis and y-axis and paths that connect these nodes determining the direction of the path. This is a fancy way for saying that the image is made up of mathematical equations.

Vector File Features

  • Vector images are great for designs that need to be versatile. Logos and fonts are a perfect example of graphics that need to be produced in all sizes to be effective.
  • Converting a vector file into a raster file is exceptionally easy.
  • Vectors always allow for transparency.
  • Vector images are resolution independent. This means when you enlarge a vector image you are simply adjusting the variables in the equations that make up the image, and the artwork lines will stay crisp.
  • However, you can’t get the same intricate colour detail with a vector image as you can with a raster image (which is not very good for photorealism).

Common Vector File Formats Used at Project House

  • Encapsulated PostScript (.eps): PostScript files are useful if you need to exchange a vector file that needs editing with someone using programs other than the Adobe creative suite, such as CorelDraw.
  • Adobe Illustrator (.ai): Great for editing vector images. This is the main file type Project House uses to produce graphics such as logos and digital illustrations.
  • Scalable Vector Graphics (.svg): Great for web-based art designs (for use as icons and shapes). They can be edited and styled easily using code, and are much more flexible than raster images when altered for our ever-changing screen sizes.
  • Portable Document Format (.pdf): This file type is extremely useful. At Project House we use pdf files to send our clients previews of designs, as well as sending finalized work to our printers. Pdf’s are independent of software program, so they can be opened and viewed using a variety of applications.

These are some of the basic differences you can bear in mind to help you get better use out of your arsenal of file types, and to assist you while making decisions with a graphic designer that impact how your brand images or artwork is used. Being able to understand a designer’s technical language will help speed up communication and ease decision-making, which can get you great design results more quickly and effectively.