Alloying is conventionally used for advancing properties of engineering materials. But with increasing degree of alloying, materials become more resource dependent and more costly, and recycling and reuse of materials become more difficult. As nowadays sustainability is becoming a more and more important index for materials development, novel strategies for sustainable materials development is highly desired. In this paper, a sustainable “plain” approach to advancing materials without changing chemical compositions is proposed, i.e., architecturing imperfections across different length-scales. Novel properties and performance can be achieved in the “plain” materials with less alloying or even non-alloying. Basic concept, principle, as well as potential applications of the “plain materials” approach will be introduced.