Somewhere in June 2009, I became self-employed. Since it involves sending invoices, I decided to create a template with OpenOffice. After creating a new invoice, I export it as PDF and email it to the customer. Saves me paper, ink, envelopes, stamps, trips to the post office, fuel, ... You get the picture.
Unfortunately I still have to hand them in to my bookkeeping office on paper, so I still have to print them once. Which is what I've been doing since June 2009. Until I tried printing invoices from Q4 2009, somewhere in December. The printer refused to print anything.