The word labels programme is very good, but you do have to ensure that the size of the label you are using there, is exactly the same as the size of the labels you are printing out.
When I was the magazine distributor for a local medical charity, I needed to print of a several hundred address labels every two months, so soon learned to to get this all correct. Could not do these in advance as people moved their address and new people had to be added, etc.
Having set it all up each time, I would always just print one sheet to check it was all okay before then telling the printer to carry on with the rest of them
4 Years On…..Health-wise, Has Anything Changed?