For the present work, two taxonomically different strains from the Culture Collec on of the Spanish Bank of Algae (BEA), Odontella aurita (O. aurita, BEA 0921B) and Tetraselmis striata (T. striata, BEA 1102B) have been selected (Figure ). O. aurita is a marine diatom (Bacillariophyceae), while the genus Tetraselmis comprises well-known species that are members of the Chlorodendrophyceae family. These strains were selected based on two main criteria: (1) high lipid (in par cular, triglyceride) accumula on and (2) rapid growth rates and significant biomass produc on to enable upscaling (for further details on the cul va on of the strains please refer to the experimental sec on and to Figure in the Suppor ng Informa on). As we have previously reported, the double bonds present in triglycerides (esters of glycerol and three fa y acids) enable easy chemical modifica on to introduce polymerizable groups, and consequently, becoming suitable materials for 3D prin ng with light. It is worth no ng that triglycerides derived from microalgae are composed of longer fa y acid chains with more unsatura ons (= double bonds) on average than triglycerides derived from conven onal oil crops such as sunflowers. Therefore, it is expected that microalgae triglycerides are promising candidates as printable materials for two-photon laser 3D prin ng, where high degree of func onaliza on is crucial. To demonstrate this, the type and unsatura on degree of the fa y acids accumulated in the two microalgae strains was monitored using gas chromatography with flameioniza on detec on (GC-FID). The results obtained are summarized in Figure (for further details please refer to Table ). Both strains contain lipids with high content of palmi c acid (C16:0). However, more interes ng is the high values of palmitoleic acid (C16:1 ω-7) present in O. aurita, as well as the high concentra on of oleic acid (C18:1 ω-9), linolenic acid (C18:2 cis ω-6) and α-linolenic acid (C18:3 ω-3, ALA) in T. striata. In addi on, both strains contain moderate amounts of polyunsaturated acids such as eicosapentanoic acid (C20:5 ω-3, EPA). Although fa y acid profile strongly depends on the strain and the abio c condi ons, the main fa y acids found in this study are in accordance with literature, and importantly, prove the presence of unsaturated groups that are key for this study.