It's not possible to choose where your orders get fulfilled; our internal systems route orders automatically. This is so your orders get printed and sent to their end destination as quickly and efficiently as possible. The fulfillment location depends on the destination address, stock availability, and manufacturing capacity.
If an order contains a product available in Europe and the end-address is in Europe, there's a high likelihood that the order will be fulfilled in Europe. And at the moment, orders going to the US are only fulfilled either in LA or Charlotte.