This August I went in search of Pthalo. Oxford does not know about Pthalo, at least not the Shorter. Google’s first hit is Wordnik: “'pthalo' has been looked up 1705 times, is no one's favorite word yet, has been added to 2 lists, has 6 comments, and is not a valid Scrabble word.” It’s still edging its way into Common English, an artist’s contraction of phthalocyanine, a synthetic compound discovered by accident in 1927. The substance inspires the blues: monastral blue, phthalo blue, helio blue, thalo blue, Winsor blue, phthalocyanine blue, C.I. Pigment Blue 15:2, Copper phthalocyanine blue, and Cu-Phthaloblue.