Hi Morshed,
You are right, thermal printers are good.
However in a lot of countries matrix printers are mandatory for bills.
As you see on this photo, only matrix (mechanic) printer can print a 3-papers roll:
- 2 for the customer (red and white)
- 1 rolled inside the printer (yellow) and has to be kept 3 years for tax control purpouse.
Marc