There are two main types of image files: vector and bitmap (also known as raster). Both files are important when it comes to graphic design, as each type has a different use. If you’re a designer, it’s essential that you understand the different formats and their suitable applications. If you’re a graphic design customer who has recieved vector and/or bitmap files, it can be handy to know the difference.
Bitmap (Raster) Images
Bitmap images are typically photographs, and any graphics created using bitmap graphics software such as Adobe Photoshop or GNU Image Manipulation Program. These images are made up of millions of tiny squares (pixels). The more pixels in the image, the higher its resolution, and therefore the better its quality. This is why a 12 megapixel photo looks a lot clearer and of a higher quality than a 5 megapixel photo.
Bitmap images are typically used on the web, where quality and resolution isn’t as high as printing. A computer screen has a typical resolution of 72 dpi (dots per inch), far fewer than the 300dpi commonly used in printing.
If you’re using a bitmap image (eg. a photograph) for printing, make sure you use the original JPG file. When photos are emailed incorrectly, or uploaded to social media, the quality lowers dramatically.
Bitmap file types include: JPG, PNG, GIF, PSD, BMP
When you zoom into, or enlarge, a bitmap image (above) too much, you’ll experience pixelation
Vector images are digitally-created graphics, typically made using software such as Adobe Illustrator, Inkscape or Corel. Rather than being made of pixels, vector graphics use points and coordinates to create smooth lines and shapes.
Because of the way they’re made, vector images can be resized without any loss of quality. This makes them perfect for use in print (banners, posters, flyers, packaging etc.) to ensure a high quality end result. Printers use a resolution of around 300dpi, so it’s important that the design or image you’re printing has a very high resolution.
Vector file types include: PDF, SVG, EPS, AI
No matter how much you enlarge a vector image (above), it will never pixelate or lose quality
Why do I need both?
When we supply logo files to our clients, we send both vector and bitmap files. This is so the correct file can be provided for a specific use.
The vector format versions (PDF & SVG) can be used for printing, signage, and t-shirts. The bitmap versions (PNG & JPG) can be used for social media, websites and email signatures.
Having both formats ensures the logo displays correctly wherever you use it.
High detail, widely-recognised
No pixelation, smaller file size
Pixelation, large file size
Less detail, need vector software to edit
JPG, PNG, GIF, PSD, BMP
PDF, SVG, EPS, AI
Illustrator, Inkscape, Corel
Web-based graphics & photos
Signage & print