A night view is revealed in the book Scratch Night View.[File photo]

After the fever for the Secret Garden coloring book, another art book, Scratch Night View, designed by South Korean company Lago Design, has also become popular. This book features night views of the world’s famous cities. According to the outline, people use a wooden pen to scratch off gray areas of the sketch to reveal yellow underneath, just like a scratch card. Many consumers say it is very relaxing and healing to do the scratching, especially when the whole view of the city is illuminated after the gray is scratched off.