Controlling the order in which monomers are linked together to form a polymer is often relatively straightforward but ensuring the building blocks are in the correct orientation is a different matter. Now, Kyoko Nozaki and a team from the University of Tokyo have made the first poly(propylene carbonate) with polymer chains built up in the form of a gradient of two stereochemically different propylene building blocks. This polymer is usually used to bind the components of biodegradable plastics. The new approach to controlling its construction could open up a new wave of polymers for a range of applications allowing polymer chemists to tailor their fine properties for specific purposes.