3-D printing is becoming increasingly utilized in the biomedical industry. This technology can be applied to the current need for accurate models of human vessels for the purposes of surgical planning and medical device validation. However, current 3-D printed anatomical models do not accurately represent the environment inside of a patient, which can lead to device failure. The Phantom Friends' project takes on the challenge of addressing this issue by developing a way to 3-D print physiologically accurate phantoms of vessels through digital analysis, mechanical testing, and validation.