You will need the following ink cartridges for the Canon Pixma TR4755i:

- Black: Canon PG-575 or Canon PG-575XL (manufacturer number: 5438C001 or 5437C001). The PG-575XL has a higher capacity and prints around 400 pages.
- Colour: Canon CL-576 or Canon CL-576XL (manufacturer's number: 5442C001 or 5441C001). The CL-576XL has a higher capacity and prints approximately 300 pages.

Compatible ink cartridges from third-party manufacturers are also available, but the original Canon ink cartridges are recommended for optimum printing results.