The file must be provided as a vector file, not as pixels. This is due to the printing technique, it does not work with pixel files.
The following explain the difference between pixel and vector files and well as information regarding how to check whether your design is created as a pixel or vector image.
There are two type of graphic files, pixel and vector graphics;
Pixel file are made up of lots of small pixels that are clearly visible when you zoom in. Pixel files are bound by the resolution from which it is created. The resolution is displayed in the number of DPI (Dots Per Inch), or number of dots per 2.54cm (one inch).
Vector files are composed of different shapes or text, which are built up from lines, each with their separate color, fill and stroke type. These lines always retain their shape, no matter how big or small you make them. It does not matter how big you make a vector file, the quality is always the same.
How to identify a pixel or a vector file?
Vector files are typically created in Adobe Illustrator and usually have one of the following extensions; AI, EPS
Pixel files are mostly made in Adobe Photoshop, and export as JPG, TIFF, PNG, PSD or BMP files.
It can happen that people send us an AI file with the assumption this is vector file, but eventually turnout still to be a pixel file. This may occur when a pixel image(eg. JPG) is placed into an Illustrator, or a pixel file is exported in Photoshop as EPS. However, this is NOT a real vector file.
How to test this yourself!
Want to check whether you have a pixel or vector image?
Zoom in to image. If the image remains sharp you have a vector image.
If the pixels are visible then you have a pixel image.