What's best - JPG, BMP or PNG?

The "best" image format for your print depends on coloration and size of your image. Here are our suggested formats:

JPG / JPEG

This format was developed to help make images smaller. In order to achieve this the image is compressed, meaning that rather than saving the color imformation for each individual pixel, an algorithm summarizes this color information, allowing it to be recreated later. To help save space and simplify this algorithm, similar or neighboring colors get grouped, and it is this which can damage the quality, vibrance and contrast in your image, in particular in areas where contrasting colors are next to each other.
 

PNG - Our Favorite

PNG stands for Portable Network Graphics. It was developed as a replacement for GIFs and can, like GIFs, include up to 256 colors per image. But it's also better, in that it is not limited to 8 Bit colors, but supports 24 Bit colors for greater quality and accuracy.

BMP

Bitmaps are, like JPG and PNG, a rasterformat. It supports color depth up to 32Bit and also has the largest colorspace possible in the available image formats. The downside of BMPs is the size of the file; your design can easily take be 20MB or more...