The video below gives you a good overview of how it works. Basically, you purchase the NIO stamper (affiliate link), which comes with a code for you to design your own stamp online. You can use their many templates, or upload your own design. Once the design arrives, you simply line up the NIO over the clear polymer stamp, press down, and you're ready to stamp anywhere you'd like.
You can easily click different ink pads in and out of the NIO if you'd like to change colors. Removing the customized stamp from the NIO and putting in a new one is easy, too. This allows you to use the NIO stamper for as many stamps as you'd like to have made.
NIO sells all sorts of ready-to-stamp items, including gift bags, napkins, tags, banners, candy bar wrappers, stickers, cake toppers, and greeting cards. I gave each of them a try.
This would be so cute for a birthday, wedding, baptism, baby shower, or other special event.
Here's a sample of some of the things I made. I did try out some of the other ink colors, but I like the black best.
I'm thinking that my I'll do a return address stamp next. Or maybe a stamp featuring the best pet ever. What would you put on a custom stamp?