Though moderate heating in a controlled environment is generally considered to be necessary, in this work we show that the most important prerequisite for obtaining high quality 2D imine polymers at the interface is the concentration and molar ratio of building blocks on the surface. With diverse monomers we have demonstrated that the concentration-in-control strategy is a general and powerful way to construct covalent single layer 2D imine polymers with high regularity at the solid/liquid interface.