Additively manufactured products undergo extreme cyclic heating and cooling sequences upon layering. Their cooling rates and melting volumes can respectively be one billion times faster and 10 trillion times smaller. Such harsh conditions constitute a challenge to design materials and processes tailored to additive manufacturing, but simultaneously offer the opportunity to tailor them to become nanostructured. With a focus on redesigning nanoprecipitation hardened steels for laser powder bed fusion, this work focuses on a modelling-oriented approach to conceive printable steels with the following features: (1) Defect free, avoiding the formation of cracks, voids, and lack of fusion. (2) Strength maximisation, promoting the nanoprecipitate formation in martensite. (3) Corrosion resistance, ensuring a minimum chromium content is present after heat treatment. Two alloy grades were redesigned with a view to improve two grades: PH17-4 and Formetrix. The former strengthened by copper nanoprecipitates, and the latter by copper and M23C6. Alloys were atomised and printed, and their heat treatment optimised through dilatometry. Multiscale characterisation and mechanical properties testing of the designed grades are presented, demonstrating the possibility for nanostructure control in printable corrosion-resistant tooling steels.