It's called a tape transfer I was actually lucky enough to learn this is in my Art I class (I'm currently in Art III). I've used it multiple times. No special science to it. Depending on the size of what you're trying to transfer depends on how long you soak it (about two minutes for something small). I wouldn't recommend hot hot water, I always used water that is a little under hot since you'd burn your hands with hot water. Always gently rub the paper off of the tape since if you rubbed too hard it wouldn't work as well and take off pieces of what you're trying to transfer. Making sure there's no bubbles in the tape is also a huge factor to a successful tape transfer because It'd defeat the purpose of it looking slick and smooth. Allow it to dry for about a minute before applying it go whatever you want to stick it on to for it to become sticky again. It's a great technic and I'd recommend anyone to try it. All you need is standard copy paper with your desires image or text and clear masking tape. ☺️ (pictures in the replies)