Do you remember the I Spy book series? You know, the books that cleverly composed countless objects in an image to provide a seemingly never-ending game of hide-and-seek. Well, each of those images were meticulously crafted by photo illustrator Walter Wick and YouTube channel Insider has shared a behind-the-scene video that takes a look at all of the work that went into capturing the images and creating the books.

The four-minute video details how Wick managed to pair up with the late Jean Marzollo, the author of the I Spy series, to create the now-iconic books that were published by Scholastic. It also dives into how he meticulously crafted each and every scene and captured it with various camera systems over the years, ranging from large format cameras and 8x10in negatives in the early nineties to the digital camera he switched to in 2004—a Canon 5D.

It’s a quick and fun watch well worth setting aside even if you don’t have the time now to watch it.