We had a small (about 30 people) wedding at some log cabins in the woods. It was not completely informal, but it was not the most formal of events, either. Because we wanted to be able to pay for accommodations for immediate family, we looked to save money in other areas.
One of the things we decided to do was print our own invitations. At work, I had access to a really nice laser printer, so off to the craft store we went. We chose these invitations because of the simplicity of the design (to match the ceremony). The kit included the invitations, response cards, and envelopes. I went to work on the weekend, and was able to print very beautiful invitations.
The ink did not run, and the quality of the paper was very good for the price. If I had to do it all over again, I would choose the same product. I would recommend these to anyone who is having a less formal ceremony. If you are having a very formal affair, I do think that the simplicity of the design would not be appropriate (and in the end, you can tell that they are printed from a printer).