For international clients I work in two different ways: purchase through Etsy Shop or directly to me, in which the payment is done by Paypal. For delivery, I usually use the CTT (Correios de Portugal - Portuguese mail) courier service, with registered priority option, which I have found very reliable. This is a fully tracked and signed for service so I will let you know your tracking number and when to expect delivery.
The portraits are first sprayed with fixative spray to stop the graphite from rubbing onto your fingers when you handle them. They are then placed in cellophane sleeves and placed in a rigid custom-cut MDF board (for the A4 international size) or a costume-cut hard cardboard cover (for bigger sizes) to ensure that they can’t be bent in transit.