Order with Printful item and stocked items.

Hi,

I would like to add custom merchandise through printful but have questions about how it is fulfilled.

Suppose I have an order come in for a few in-house products that I ship as well as a printful t-shirt on the same order. Will printful receive that order to have the t-shirt made and shipped? Then I ship the other products from my store? 

Just trying to figure out these logistics. I think this would be a great addition to my store.

Thanks,
Jason

I am trying to figure out this same thing with Printique fulfilling my open edition prints while I fulfill my limited edition prints from home. So far I haven't been able to find an answer.