FREQUENTLY ASKED QUESTIONS - FAQS
WHAT IS A VECTOR GRAPHIC?
A vector graphic is made up of lines and curves, allowing it to be scaled up or down without loss of quality. An EPS
file is an example of a vector file format.
NOTE: Not all EPS files are vector graphics. Adobe Photoshop also saves raster graphics in EPS format. If
you open a vector file in Photoshop and save it, it will become a raster graphic.
WHAT IS A RASTER GRAPHIC OR BITMAP?
A raster graphic or bitmap is made up of patterns of picture elements, called pixels, these are the blocks you see
when you zoom into a digital image too far. A JPEG or TIFF file is an example of a raster/bitmap file format.
When a raster/bitmap file is scaled up or enlarged, it will produce a poor quality image. When printing bitmap files,
the image reproduces exactly as it is stored - in other words, it is resolution dependent. If the original file is 150dpi,
opening the file into software (such as Photoshop) and up-scaling the resolution to 300dpi does not make the image
now 300dpi.
WHAT IS HIGH RESOLUTION/LOW RESOLUTION?
In digital/electronic imaging the measurement of printout quality for raster images is expressed as the number of
dots per inch (dpi). Image resolution typically ranges from 72 dpi for screen viewing (low-res) to 720 to 1800+ dpi for
professional printing (high-res).
Generally the higher the resolution, the higher the quality of the output, and the larger the file size. If you have a
low resolution image, or you “stretch” a small raster image into a larger size, the image will print with jagged edges
and appear pixelated. Resolution and size are different, but proportional. For example, a 70 x 70 mm image at 300
dpi resolution will appear to be the same quality as a 140 x 140mm image at 150 dpi. Every time you increase the
measurements of a raster file, the resolution decreases accordingly.
NOTE: Once the resolution of a raster file is reduced it cannot be restored. Images from the Internet or
any kind of web site are usually 72 dpi GIF, JPEG or PNG files, which cannot be reproduced in large format
printing due to the poor quality. Colour and resolution, and ultimately quality are compromised from these
low resolution images to allow rapid transfer through the Internet.
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Full Colour Digital Direct Print
