When Amanda Rulton picked up a cheap coloring book and some felt-tip pens, she didn’t expect the activity to stick. It came when she was in the middle of a health crisis. Eighteen months ago, she had ...

Crayons, of course. Scented markers. Colored pencils, presharpened. And coloring books by the jillions. Why do people like coloring so much? For grown-ups, I can totally get the nostalgia — and the ...