Differences between vector and pixel-based images
All clients would like their logo to look its best on a product. Interimage regularly receives files that do not meet the requirements for supplying artwork. For this reason, we have explained the difference between a vector-based and pixel-based image below.
A vector-based graphic is built up using lines that retain their shape at all times, regardless of whether the image is being scaled up or down. This means the image quality is always retained. However, vectors are unsuitable for creating photographic images.
Images that consist of pixels contain many, in some case millions, of small squares. These become visible when you zoom in on the image in great detail. With this type of image, your options are determined by the resolution of the image, which is indicated in “dots per inch” (DPI). This is equivalent to the number of pixels per inch. These are only relevant when the image is printed. The use of pixels means that images of this type cannot be enlarged infinitely without a loss in quality.
How can I distinguish between vector-based and pixel-based images? A vector-based file is often in EPS, PDF or AI (Adobe Illustrator) format. The most common pixel-based formats are JPG, PNG, GIF, TIFF and bitmap.
A PDF file can contain both vectors and pixels. PDF is a universal format that always ensures the same, standardised output. Practically all programmes are capable of exporting to PDF. We occasionally come across EPS, PDF or AI files that are sent on the assumption that they are vector-based files and that are subsequently found to be pixel-based files. In those instances, the file is often a pixel-based file such as JPG that has been saved using one of the file formats mentioned above. However, it is not possible to convert pixel-based files to vector-based files.
With regard to sending in artwork, Interimage recommends the use of vector-based files, especially in the case of logos. If you want to check whether your file is vector-based or pixel-based, you can do so by viewing the image with a high zoom level.
The minimum requirements for photos that you wish to use are 300 DPI and 1:1. If you are in any doubt, feel free to send the file over to us.