We partner with several outside backup facilities in the US and Europe to help us manage order volumes. The more facilities we partner with, the more flexible our fulfillment network is which helps us fulfill and ship your orders on time. We involve said facilities in the production process in case of an unexpected increase in order volumes, or emergencies.
Each backup facility is tested for quality, making sure the production and speed standards are as high as Printful's. However, if you wish to opt out of using backup facilities, you can do so by going to your Printful Dashboard > Settings > Stores > Orders.