Canon Selphy printers are compact photo printers with small, inkjet cartridges. Recycling the cartridges helps the environment and keeps the plastics out of landfills. To assist you, Canon provides a free shipping label with postage paid. Once you send the cartridge, they break it down into its basic parts and reuse them in new cartridges.
Go to Canon's Recycling Program website (see link in Resources).
Under the Recycling Program logo, see the "Choose Below" bar and select "Printers & All-In-Ones." Now click "Compact Photo Printers." Scroll down in the list of printers and select your model.
Type in the serial number of the ink cartridge you want to recycle--it's on the top or back of the cartridge--in the box below the list of printers. Click enter.
Type in the contact information requested by the form. This will include your name and address for the printed label, and your e-mail address so they can send you the label. Click "Submit."
Check your e-mail in a few minutes for the label. Print it and tape it to a box containing the cartridge. Take it to your local post office to mail it. Shipping is already paid for--you'll just need to drop it off.