We print on demand with Lulu (http://bit.ly/stores-lulu-com-arobooksworldwide) for books and Zazzle for art (http://bit.ly/zazzle-com-arobooksworldwide). This means that your order goes to Lulu and Zazzle and not to us.
Lulu print books as close as they can to the delivery address to minimise shipping. This means that orders for the USA are printed in the USA, orders for Britain are printed in Britain. Lulu themselves are based in Raleigh, North Carolina.
Orders at Amazon, Barnes & Noble and other web shops are dealt with in a similar fashion. Books are printed and shipped to order. Orders from bookshops work a little differently. We receive information from Gardners and then place an order on Lulu for shipment.
So although we have no stock — and we rarely see a book — we have an unlimited supply.