<Tr> <Th> Printing press </Th> <Td> c. 1440 </Td> </Tr> <Tr> <Th> Etching </Th> <Td> c. 1515 </Td> </Tr> <Tr> <Th> Mezzotint </Th> <Td> 1642 </Td> </Tr> <Tr> <Th> Aquatint </Th> <Td> 1772 </Td> </Tr>

Where is the heating element commonly found in a thermal printer