The most common mistake in communicating artwork often stems from clients being unable to provide the original files that were used in the creation of the logo. Since the main use is often on letter heads or internal presentation the logo they have is a bit map of some kind: that is made up of dots and in a file format such as a .jpg, .bmp, .gif or .png file. On rare occasions, if the file is large and of high resolution, this may suffice. More often it is not possible to scale up the image to the required size without loss of quality. The file needs to be in a scalable vector format, which allow unlimited scaling. Typically these files have the extension .ai, .cdr, eps. and sometimes a PDF, often created in a programme like Adobe Illustrator.