In 1791, the king of Korea installed a life sized painting of a bookshelf behind his throne. King Jeongjo ruled Korea from 1776 to 1800 and was too busy governing to read as much as he wanted. So he had court painters create trompe l'oeil screens (paintings so lifelike they fool the eye), stacked with books, vases, and trinkets. His own officials reportedly mistook the painted shelves for a genuine bookshelf. The king later explained that looking at them let him feel the pleasure of touching his books, even on the days he had no time to open one. The style, later named chaekgeori (roughly "books and things"), spread from the royal court to wealthy studies and eventually into merchant homes by the late 1800s. A wall of books had become a stand in for the mind of the person who owned it, whether they had read any of them or not. The same trick turned up in Washington in the early 1970s. A journalist visiting the Senate Press Gallery went looking for the books on a shelf reserved for reporters. Instead he found glued on spines mounted to a dark board, with strips of wood standing in for shelves. Decades later, someone turned the same illusion into a business. A company called Books by the Foot sells curated walls of hardcovers by the linear foot, starting at $12.99 a foot, pulled from a warehouse holding more than 4 million secondhand books. One interior decorator ordered 200 feet of what the company calls "solid literature," installed within days for a client's dinner party. Then came Zoom. In 2020, as video calls moved into people's living rooms, the New York Times put a name to what everyone was quietly doing with the shelves behind them: bookcase credibility. A parody account mocking people's staged backgrounds picked up more than 78,000 followers within weeks. By 2024, a San Diego designer had renamed the same instinct bookshelf wealth in a TikTok video, and Cambridge Dictionary added the term to its list of new words that April. A shelf can display what someone has spent years reading, or it can be built, glued, or rented specifically to make a stranger believe they have.