This video shows you how to create a larger file (fat quarter) for printing at a fabric-on-demand service like spoonflower.com or fabricondemand.com.  I've used both of these services.  You can add as many photos or projects to a fat quarter as will fit in the space of the file you create. 

As I mention in the video, this technique can also be used to create a yard size file.   The turn around time to receive your printed fabric is about 7 - 14 days, so plan accordingly.