Quality Artwork. Raster vs. Vector Images
By Pete Apo
There are two artwork types: Raster and Vector images. To print quality graphics requires high quality or high resolution artwork. We recommend, if possible, to provide us with vector artwork which is created in a vector software program like Illustrator or Corel Draw. If you are unable to get this file type you can also provide us with a High Quality raster image with a minimum DPI resolution of 300. If you are unsure what file type or what resolution image you have you can read further or contact us.
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).
Pete Apo is the owner of Impact Northwest located outside Eugene, Oregon in Creswell. He has over 17+ years experience in the garment and promotional item printing industry and is founder of the clothing and product line The Rusty Hawaiian. Impact Northwest is a provider of custom screen print, embroidery, dye sublimation and promotional items to Lane County and the surrounding communities.