Our BIC clients told us to be on the look out for adult coloring books and we’ve been seeing them in airports, waiting rooms and even on MetroNorth trains. In fact, meet up groups are forming where people can sit together to chat, color and enjoy each other’s company. Many adults are finding that revisiting this old hobby is a good way to unplug, unwind, relax and feel happy. Coloring books for adults — a genre once considered little more than a novelty — is suddenly a big business for publishers and retailers alike. The Nielsen data company estimates that some 12 million were sold in 2015, a dramatic jump from the 1 million sold the previous year. Barnes & Noble, Wal-Mart and Michaels executives said the growing interest in adult coloring books has also prompted a surge in sales of a host of related art supplies. Sure, some people are perplexed by grown-ups taking cues from the kindergarten crowd, but we’ve grabbed our BIC Evolution colored pencils and have jumping in with a full technicolor force.