Baked in! Ha!
Sublimation is the process of taking Dye Sublimation Ink... Printing your image onto specially made transfer paper then using a commercial heat press to press the image onto any sublimation blank. Ceramic mugs are coated for sublimation (well you have to buy them that way they don't automatically come that way in the stores) for example and then I use a mug press to essentially bake the image into the tiny pores in the ceramic. It's like a permanent tattoo... For whatever substrate you're sublimating.
I have a special printer for this too as well as two presses. A mug press and 16" x 16" big press for doing many things...