The technology readiness level of self-microfabrication is between 2 and 3 301 when considering the hair follicle organoids as proof-of-concept. Scaling up organoids for medicine has revealed significant challenges, but potential solutions can be leveraged for material-producing organoids 302,303 (Table ). Unlike medicine, self-microfabrication faces fewer regulatory constraints but emphasizes cost-efficiency 304 . Focusing solely on costs at this stage would be shortsighted, as it overlooks future innovations, automation and economies of scale. Much is to learn from the cultivated meat sector that has even stricter cost requirements 307 . Biological materials may balance the cost by focusing on high value products 308 that exhibit high mechanical performance . Addressing production rates and biological constraints Growing biological materials is generally slower than producing their synthetic counterparts. For instance, Nephila spider MA silk is produced 30 times slower than Kevlar, i.e. 5 µm diameter at 10 cm/s for silk 332 and 10 µm diameter at 80 cm/s 333 . However, spiders use liquid silk preliminary stored in the ampulla. Accounting for protein synthesis rates would likely reveal an even smaller production rate than synthetic polymers, as observed in other species 334 . Although essential, this comparison is somewhat inequitable since industrial polymer synthesis has already gone through decades of optimization. Synthetic biology can also accelerate cell cycle and optimize the growth and metabolism of tissues 335 . Indeed, modeling growth rates and gene regulation 336 highlight potential improvements 337 and trade-offs 338 . To compensate growth limitations, material-producing organoids may produce in parallel to increase the throughput. Organ production units are self-organized and compact, potentially enabling their large proliferation in number, facilitating their parallelization . Since biological materials aim to improve sustainability compared to fossil-based solutions 177 , the environmental impact of biotechnologies should be considered 339 . Large scale selfmicrofabrication may also eventually compete for arable land to produce biomass, as already observed for biofuels . Potential solutions include polycultures, yield optimization 341 and circular economies with the valorization of wastes 342 . Challenges in developing material-producing organoids are mostly addressed in Section 6. Beforehand, we present a theoretical framework for self-microfabrication to examine key concepts.