The functionalized lactate esters were implemented as new bio-based monomers for DLP 3D printing (Figure ). In order to obtain a printable formulation, the addition of a crosslinker is necessary. To this aim, the crosslinker N-lactoyl ethanolamine dimethacrylate ester, abbreviated to DME, (see Figure ) was chosen as an ideal candidate, since it can initially be sustainably sourced by upcycling poly lactic acid (PLA) waste, which itself is sourced from biomass. The final aim is then to re-synthesize DME by upcycling the structures printed with this first ink formulation (see section below). When developing the ink formulation, a ratio of 9:1 lactate ester monomer/crosslinker with 2 wt% of phenyl-bis-(2,4,6trimethylbenzoyl)-phosphinoxide (BAPO) as the photoinitiator was found to be printable. However, some over-polymerization could be observed. This issue could be overcome by adding 10 wt% of methacrylic acid as a reactive diluent, resulting in a formulation with very good printability of finely detailed structures. Since methacrylic acid (MA) can be sourced from biomass, specifically citric acid and itaconic acid obtained from fermentation of sugar, its addition does not reduce the overall biobased content. All three inks were printable with comparable exposure times ranging from 22 -28 s at an intensity of 28 mw/cm 2 for a layer thickness of 100 µm. Slight variations in the kinetics of the photopolymerization could be observed, which can be quantified by the critical energy Ec below which no photopolymerization occurs. The Ec values, listed in Table again follow the previously observed trend of faster kinetics corresponding to shorter alkyl chain lengths. The printability of the three ink formulations containing the different lactate ester-based monomers was further tested with complex 3D models such as a lattice (SI Figure ) and a water lily as test geometries, resulting in very defined structures for all three ink formulations, depicted in Figure .