There are numerous techniques for printing on objects. Hot stamping is one of them. It entails sticking an already printed film on to the object by using a sort of giant iron. This technique is used often for textiles but it requires a lot of adjustment of settings to achieve a good quality result.
There are two different techniques. The first one, which is the oldest, consists of making a kind of stencil, which will take the form of the part to be marked, like a stamp. This stencil is heated up and then strikes the substrate thanks to the use of a hot stamping machine. The second technique is digital and does not require the creation of a stencil, as that is replaced by the printhead on the digital hot stamping printer.
Hot stamping consumes quite a lot of inputs because the printed films have to be paid for and these are different for each file. In terms of speed, this technique does not allow for runs of more than one product per second, so it is relatively slow.