Look in the Yellow Pages for wholesale paper houses in your area, explain to them the kind of labels you want, and then buy your supplies in mailing list quantity lots. Then as you receive orders for your list, just run your master copies through the machine onto the labels and send the labels out to your customers. Be sure to keep a log on the front of each list, and note the date - name - and kind of offer sent out by each renter.
Try to find out as much as you can about each of your list renters, and the type of materials they're sending out - and then ask them to check back with you on their results. By all means, you'll get more renters if you offer some mailing list sort of compensation for any nixies returned to you - and at the same time, you'll be able to keep your list free of undeliverables.
Such an offer might be one new, and guaranteed fresh name for every undeliverable returned to you within 60 days from the date mailing list of their order. If there is one thing I can't say enough it is that the most important part of your mailing campaign is your mailing list. It is vital that you put the right amount of energy into learning about lists - who to mail to - so that your mailing efforts aren't wasted.