A dye-sublimation printer is a special kind of printer that can make pictures on paper using heat and special ink.
First, you need a special kind of paper that is covered in a thin layer of material that can absorb ink. This is called "transfer paper".
Next, you put the transfer paper into the printer and print your picture onto it. But, instead of using regular ink like a normal printer does, the dye-sublimation printer uses special ink that turns into a gas when it gets really hot.
After you print the picture onto the transfer paper, you need to use a special machine that heats up to a very high temperature. The transfer paper with the picture on it is placed face down onto a piece of fabric or another material, like a mug, t-shirt or a mousepad. The heat from the machine causes the special ink to turn into a gas and soak into the material. When it cools down again, the ink becomes solid again and stays embedded in the material.
The result is a picture that looks bright, colorful and lasts for a long time. Because the ink becomes a part of the material, the pictures made with dye-sublimation are usually more durable than regular printed pictures that can easily be scratched or damaged.