Sumptuous fore-edges - sprayed a bright color, stenciled with city skylines, made to look like pointy teeth - used to be relatively rare. But in recent years, publishers have brought decorated edges to the masses. Edge-painted books are now so widespread that you can find them at Walmart. The feature has spread from romance and fantasy to horror, thrillers and even literary fiction; it’s spread from works by famous authors with ravenous followings to those by debut novelists hoping to make a splash. It even has a (horrifying) portmanteau: spredges. On social media, readers show off floor-to-ceiling shelves crammed full of these books - spines facing inward, of course.