Which side is the inside and which side is the outside?! I DONT EVEN KNOW, I'M FREAKING OUT HERE! This crazy little number can be worn Mathematicool-side-up or Periodic Table-side-up, whichever floats your boat at any particular moment. Change your mind about your outfit halfway through the day? Feel the spontaneous need for something different? Not a problem with this dress! Blackmilk Clothing Periodic Table vs Mathematicool Inside Out Dress size medium. No tag because it is an inside out dress so the tag was removed to wear. Excellent condition no pilling or snags. Barely worn! Please give her the new home and the attention she deserves!!