Go to the printer that you are looking to buy. Find the Specification sheet, or detailed spec sheet. Near the end, possibly with the diamentions and weight should be a set of figures under Electrical Requirements, Rated voltage.
In the UK the voltage is 220/240 @ 50Hz, in the USA it is 110v @ 60Hz. I am not sure of the voltage or Hz in all of Europe but most Countries I think are 110/120, you should be able to find out with a Google search for the countries you are going to.