Known also as Pixel based artwork, raster images are the most common form of digital imagery found on the internet, known by familiar files names such as JPEG’s, TIF’s, BMP’s or PNG’s. Raster image resolution is represented by DPI (dots per inch) this number indicates how many pixels a particular image consists of in a one inch space. Images, if saved directly from the internet, will have a resolution of 72 DPI, which is often times TOO LOW of quality to be blown up and work well on a t-shirt or other high quality prints.

If these types of low quality images are used and then enlarged, “pixelization” or blurriness will occur. Another problem low quality artwork or non-vector images have is the ability to be altered or prepared correctly for printing, like separating colors, reducing colors, or creating any separating space that is sometimes needed for various printing. To avoid having to pay additional artwork charges it is best to provide your printer with vector artwork or at the very least a high quality (300 DPI) raster image.

Vector images or artwork and it’s technical definition is a bit complicated to understand. Simply put vector files are a type of graphic image that uses mathematical algorithms and not pixels to create artwork. This allows the image to be scaled or modified ad infinitum without loss of quality or resolution. These images are easily resized in a vector computer software program and are a better quality graphic than raster images. They can also offer superior color separation systems which makes them perfect when using for screen printing.

Vector images are created in vector software like: Adobe Illustrator, Corel Draw or Sketch. Often times people will take a regular raster image, open it and save it in a vector software, thinking that this makes it a usable vector image. This is not true and when opened by the artwork department, the image will still be a raster image. In order for images to be vector they have to be created or traced in vector software then saved in a format that saves the vector information, like a native software format (.ai, .cdr, .sketch), Encapsulated Postscript (.eps) or Portable Document Format which has embedded vector information! (.pdf).

If you still are not sure what type or quality image you have it is not a problem we are happy to assist you. Please feel free to contact us with any questions regarding your artwork or just e-mail us your image and we can tell you what type and quality image you have.

Wikipedia – Vector Graphics

Pixel Art

Vector vs. Raster

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