I'm at an age in life where my finances should be totally secure, but like many Americans I still sometimes find myself short of ready cash when it comes time to pay the monthly bills. So I thought I'd dig out my file on past-due stickers and look at some of the ways vendors have tried (and still try) to encourage prompt payment. If you're at all concerned that I would, in fact, have a file of past-due stickers, I can only say "thank you." It concerns me, too.

All of the images in this column are from rubber-stamp and stock-label catalogs published from 1919 to 1958.

When I was in the magazine business, I was horrified to discover that even those subscribers who had been tricked by a free offer into agreeing to a 12-month subscription were sent nine months' worth of bills trying to collect. Each invoice was more aggressive and even though every round produced diminishing returns, I was assured by the circulation department that it was still worth the money to send out invoice number nine. But after that, it seems, not enough people paid to make it worth sending out invoice number 10. So we gave up. Clearly one key to effective bill collecting is to harass people to death.

And I have, sadly, worked for corporations that, as a matter of principal, delayed paying bills as along as possible, even when they had the money. In these cases no amount of stickers or rubber-stamps on an invoice would make the difference. I often advised those suppliers I counted on most to threaten a work-stoppage or to hold products and services until they were paid. So another key to good bill collecting is to avoid extending credit beyond a period through which you can survive. You might think getting the balloon contract for Neverland Ranch is money in the bank, but you really don't know!

If you do find yourself either being owed money or owing money, there seem to be a few tricks, though I can't help but wonder if they haven't grown a little stale and predictable by now. It may actually be a lot more effective to show up with a baseball bat on day 31 of that 30-day invoice, but for some reason that's frowned upon.

No, just about all the bill collectors I've run across say that it is best to start out being extra-nice. In the early stages you're likely to receive "gentle" reminders and "friendly" notes that give every possible benefit of doubt and may, in fact, even imply that the vendor has possibly made a mistake and simply needs clarification as to when you mailed that check. These notifications are almost apologetic.

If you send in your payment at this stage, everyone will still be happy and no consequences are implied or threatened. Sort of like when your boss tells you "by all means get over your cold and don't worry about a thing here." You get a free pass in the early stages.

The next tactics tend toward either the humorous or slightly indignant. You're clearly in more trouble, and the vendor is getting kind of pissed, but we're all still maintaining civility.

After humor it's time to try guilt: How am I going to feed my new baby or get that operation for my sick puppy? Bill collectors say that this stage and is often the one that gets results. They call it the "make it personal" stage and suggest telling your deadbeat customers that you're not able to pay your own bills now, thanks to them.

If humor, guilt, or a number of friendly reminders don't work, it's time to bring out the big guns and start the threats. If the bill hasn't been paid yet it may not make a difference, but the threat of poor credit reports, third-party bill collectors, and other tactics is paraded out now in increasing urgency. The problem is, many companies never follow through on these threats, so some people have come to discount them. That's probably why the guilt step still gets the best results -- if you can't appeal to the human being behind the debt, you're probably not going to get any further.

Based on rubber-stamp designs from the 1920s and '30s, vendors back then were more inclined to be downright rude, but that seems to have lost favor by the '50s and '60s when good customer relations became the priority. Even the most aggressive bill collectors these days are polite and usually end even the most painful conversation with "thank you for using Citibank," or the like.

I hope none of you ever get past the "friendly reminder" stage with bills and experience the other tactics bill-collectors use. Just remember that for every past-due reminder out there, you can always give the same answer: "The check is in the mail."