It seems fairly obvious that they don't allow custom designs. If you want to print your own stuff, go to a maker space. Quality control is important for a company like Amazon, and custom designs make that impossible. A small batch of items is the logical place to start a service like this. I'm sure over time they'll steadily incorporate proven designs onto the platform; probably they'll also let people submit designs and get a cut of the design, just like books. But, there will need to be a rigorous quality control process in place before the platform can be that open.
It seems fairly obvious that they don't allow custom designs. If you want to print your own stuff, go to a maker space. Quality control is important for a company like Amazon, and custom designs make that impossible. A small batch of items is the logical place to start a service like this. I'm sure over time they'll steadily incorporate proven designs onto the platform; probably they'll also let people submit designs and get a cut of the design, just like books. But, there will need to be a rigorous quality control process in place before the platform can be that open.