Tread lightly, in periodic table elements

Spelled out in chemistry, said in Heisenberg's voice. This Breaking Bad doormat is for science nerds who don't mess around.

Natural coir comes in sizes from 16"x24" up to 36"x72" and likes a covered porch. The all-weather version, in 18"x30" or 30"x47", handles rain and hoses clean. Give it to the chemistry teacher, the lab tech and the friend who rewatched all five seasons twice. This design is retiring. When it's gone, it's gone. Size questions go to Tammy Sandwiches, our doormat matchmaker (a very good dog), or to How do I choose a doormat?