Vector Art vs. Raster Art
“You can just pull the logo from my website.”
This is something we hear all too often when we ask for a copy of a logo to begin a project. The problem is the resolution of a website graphic is usually too low for printing.
Almost any image found on the web is a JPEG, GIF or PNG file. The image is similar to a photo: a raster (gridwork) of dots, each with a specific color value and brightness. The web displays images at 72dpi (72 dots or pixels per inch). Raster images with a low DPI like 72dpi look nice and crisp on the web. They are made this way because the smaller file size helps web pages load quickly, but they do not print well. When the image is enlarged beyond its intended use, the dots are discernible and the image becomes bitmapped, or jagged.
To correctly print an image, it should be at least 300dpi, a much higher resolution than the web displays. Resizing a low DPI image pulled from the web for a print project doesn’t work because the same finite number of pixels only get bigger and begin to distort.
EPS, AI and PDF files are excellent for graphics such as logos that frequently require resizing. They are vector art, so no matter how large we make them, the image is mathematically built by the computer and always remains smooth. Also, vector art colors can be separated for spot color printing. This helps make sure your files match your brand's colors and is why vector files are used for making promotional materials like hats and shirts.
If you have had your logo professional designed, you should receive a folder containing different files for different uses: PNG, GIF and JPG for use in your Office documents and your website; and PDF, AI, and EPS files for printing. Even if you can't open some of these files, we can and they are usually what we need to give you great looking printed pieces.
One note: A PDF can be either a vector or a raster file. It depends how the PDF was created. If you’re unsure, send it to us. We can let you know if it is usable for your project.