PIXMA TR8620a CLI 251 vs 281 Ink Cartridge Compatibility

[marvineggert]

I recently purchased a printer and find that it calls for CLI 281 cartridges.  Yet, when I go to a retail store, all the PIXMA cartridges are 251.  What is the difference?

[Tiffany]

Welcome to the Canon forum!

So that the Community can help you better, we will need to know the exact model Canon printer you are using. Any other details you'd like to give will only help the Community better understand your issue.  If this is a time-sensitive matter, click HERE search our knowledge base or find additional support options HERE

Thank you!

[marvineggert]

My printer is a TR8620a

[Stephen]

Thank you for the updated information! 

Your printer is NOT compatible with 251 inks. These are the ONLY inks your printer is compatible with: https://canon.us/3ipDm6u 

[FLJohnson]

You didn't actually answer the original poster's question. What is the differences between the 251 cartridges and the 281 cartridges? Are the electronics different. Are the inks different? Are the mechanical aspects of the cartridges different? In how many ways are the cartridges not interchangeable?