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Poster Design: Working with Images

Whether you are planning to present at the Spotlight on Student Research or gearing up for your conference poster presentation, this guide should help you avoid some of the most common mistakes and provide some ideas to help you get started.

File Types

Several file types are typically used in the graphics industry. they can be divided into two general categories; raster and vector.

http://modassicmarketing.com/wp-content/uploads/2012/07/image-file-types.jpg
Source:http://modassicmarketing.com/understanding-image-file-types/

  • Raster images use color pixels to build an image. The closer you zoom in, the more apparent the pixel. The more an image is zoomed or re-sized, the more apparent the pixelation. Raster images are easily incorporated into most graphic design platforms (PowerPoint, Illustrator, Preview, etc.)
  • Vector images use mathematical formulas to construct images. This allows for more flexibility in scaling since each part of the image is based on a coordinate system. Master images should be created in raster format since they never lose resolution. Adobe products tend to focus on vector images.
  • Image sizing should be 300 DPI for printing. 72 DPI can be used for display-only images.

Where to find images

Sure, you've heard of Google Images. But have you heard of the resources below? Just remember to properly attribute any images that appear on the poster, even your own!

File extensions

From modassicmarketing.com

JPG
JPG (or JPEG) is a raster image that is often used for photographs on the web. JPGs can be optimized, when saving them out of photoshop, to find the perfect balance of small file size and high quality. On the web, you want your images files to be as small as they can be so your site loads quickly, but large enough to still appear crisp and not pixilated. A JPG can’t have a transparent background so they are always in the shape of a rectangle or square with a solid background.

Best use = rectangle or square photos and photographs on your website.


PNG
PNG is another raster image type. For the general marketer, the main difference to understand between a PNG and JPG is that a PNG can have a transparent background and is generally larger and higher quality. Therefore a PNG is ideal for saving logo files for websites because they can be placed over a colored background.

Best use = logos, icons and other images where a transparent background is preferred.

GIF
A GIF is another raster image type. A GIF is formed from up to 256 colors from the RBG colorspace. The fewer colors and shades contained in an image, the smaller the file size. Therefore a GIF is ideal for images that use just a few solid colors and don’t have gradients or natural shades. You wouldn’t want to use a GIF for a photograph.

Best use = simple web graphics such as web buttons, charts and icons.

TIF
A TIF (or TIFF) is a large raster file. It has no loss in quality and therefore is primarily used for images used in printing. On the web, because of load time, you generally want to use smaller images such as JPG or PNG.

Best use = images and photographs for high quality print.

EPS
An EPS file is a vector file of a graphic, text or illustration. Because it is vector is can easily be resized to any size it needs to be. An EPS file can be reopened and edited.

Best use = master logo files and graphics and print designs.

AI
An AI file is a proprietary, vector file type created by Adobe that can only be created or edited with Adobe Illustrator. It is most commonly used for creating logos, illustrations and print layouts.

Best use = creating logos, graphics, illustrations.

Editing vector files and saving “in outlines”
Vector files such as AI and EPS can remain editable so you can open them back up in Illustrator and edit any text or other elements within the graphic. With images that contain text that are saved as a JPG, PNG or GIF, you would not be able to reopen and edit the text.