Well, you may wish to just make text boxes in the forum of a table in your favorite work processor and then adjust them to match the paper stock you will be using, Then you can just use what ever cell still has a sticky label.
Back in the day, I used to use MS publisher(anyone here remember word art?) for this and it was perfect, just take measurements and use the in program rulers to make invisible lines to help you line things up.
Anything with a built in ruler(and your own ruler) like open office should work, but remember, you will have to do some tests of paper to ensure everything is just as you want it.