Abstract Our parent R01 titled “Multi-parametric anthropomorphic MRI Phantoms technology for reliable and reproducible structural and quantitative MRI” aims to develop materials, technology, tools and processes for manufacturing quantitative anthropomorphic Magnetic Resonance Imaging (MRI) phantoms. Unlike existing solutions, which often use discrete compartments or geometrical shapes filled with solutions representing a single physical parameter, the aim is to enable fabrication of phantoms that truly mimic the contrast heterogeneity of tissue in 3D. Motivated by a rising need for quantitative measurements in MRI driven by precision medicine and the use of data science tools for biomarker discovery. With the rise of methods such as fingerprinting, and accelerated reconstruction, quantitative MRI (qMRI) is closer to the clinics than ever. However, quality control with a quantitative MRI phantom that mimics the complexity of tissue structure and contrast mechanism is necessary to ensure the accuracy of the results. Between 2014-17 the National Institute of Standards and Technology (NIST) hosted workshops working towards standardizing qMRI. The recommendation paper lists outstanding needs, which the parent grant aims to address, and will be partially addressed by this administrative supplementary. The original parent grant lists two approaches: (a) Quantitative 3D stack of thin slices. This approach is inexpensive and easy to reproduce by labs with moderate equipment and skills. (b) An advanced approach of boundaryless fully 3D phantoms that will be fabricated via inkjet 3D printing of hydrogels and plastics and would enable true high resolution 3D structures with heterogeneity that mimics human anatomy. Our phantoms will be based on digital design (brain-web and the MGH phantom) and hence will have a digital twin for comparison with the physical phantoms. The progress we made through Y1 of the parent grant is enabling us to achieve a milestone of a phantom which is based on both brain-web and the MGH phantom, is made of a few thick slabs which provide true 3D morphology and without boundaries. This phantom will mimic B0, B1, Brain morphology and quantitative relaxation parameters for accurate contrast. Use cases include: protocol development for research clinic and industry, system calibration validation and Q/A for morphology and qMRI, MRI receive and transmitter coil development, Image reconstruction performance validation. Testing, validation and Q/A of automatic prescription methods.