As long as your Operator ID is displayed (as directed by the CAA) on your drone, it doesn’t really matter what it is printed / written upon.
Some will be happy with hand written masking tape, some will buy printed labels, some will buy label printers and other may choose something else.
The choice is down to the individual, there is no wrong and no right. 
There’s are several companies offering custom made laser engraved aluminium tags