the incomplete guide
At a Glance:
- JPG & PNG are Raster images and can be displayed online.
- EPS are Vector images and cannot be displayed online
- JPG cannot have a transparent background
- EPS and PNG files can have a transparent background.
- EPS files are for professional printing
- JPG can be printed if saved at 300dpi or greater
- PNG files should never be used for printing.
Vector vs Raster images
Raster files, also known as bitmap images, are composed of pixels arranged in a grid. These pixels contain colour information and are suitable for complex and detailed images, such as photographs. However, resizing raster images can result in a loss of quality as pixels get stretched or compressed.
Vector files use mathematical equations to define shapes, lines, and curves. They are resolution-independent, allowing for unlimited scalability without loss of quality. Vector graphics are ideal for print applications, such as logos and illustrations.
EPS or .eps: Excapsulated Postcript
Where Adobe Illustrator files are used in the creation of vector artwork, EPS files are the completed vector files ready to be used or sent elsewhere for use. For example, a vector file created in Adobe Illustrator can be saved as an eps file and then can be sent to a print shop, to a sign maker, or to a promotional product company. Unlike the AI file, the EPS is can be opened by many different kinds of image-handling software, making it easier to share than an AI file.
JPG or .jpg: Joint Photographic Experts Group
JPGs are probably one of the most common image files you see. As a raster file, it’s resolution is locked. If it was created with a resolution of 300 ppi (pixels per inch), the resolution can only be 300 ppi or less. A 72 ppi image cannot be made higher resolution. The best it will be is 72 ppi. At 300 ppi, a JPG is great for printing, but at 72 ppi, it’s only do for the web or email viewing. This files type does not support transparent backgrounds.
PNG or .png: Portable Network Graphics
When it comes to images on the web, the PNG (.png) file format is very popular due to its low resolution and smaller file size (both qualities lending to faster page load times and such). Also, unlike the JPG, the PNG supports transparent backgrounds, making easy to use for websites with varying background colors and textures. Due to its lower quality however, it’s typically not used in the printing environment. As you may have guessed, the PNG is a raster file.