Personalized My Daddy is the World’s Best Materials Scientist Infant Romper. My Daddy is the World’s Best Materials Scientist Infant Romper - White has cute world’s best design with slogan for the son or daughter of an Materials Scientist Meet your new favorite outfit! Keep dressing simple with this one piece, lap shoulder t-romper. Super soft and perfect for baby's sensitive skin. 5.5 oz. 100% combed ringspun cotton premium jersey (CVC Colors are 60/40; Heather is 90/10 combed ringspun cotton/polyester)