Personalized Pi Day March 14 Math Lover Science Baby Bib. Whether you're attending a math-themed party or just want to express your geeky side, this Pi Day apparel is a must-have. Grab yours today and wear your love for math proudly! Our Baby Bib is rated high in convenience and durability and with a variety of fashionable colors, your baby can be trendy. Mix and match to any outfit. 100% cotton ring spun combed heather colors are cotton-poly. Width 7.75", Length 11.75"