print on demand
noun [ U ] publishing specialized uk/ˌprɪnt ɒn dɪˈmɑːnd/ us/ˌprɪnt ɑːn dɪˈmænd/ (abbreviation POD)
只在收到订单之后印制（图书或其他文件）
a way of producing books or other documents in which copies are printed only after they have been ordered