The Brother MFC-J4340DW takes the Brother LC436 ink cartridges.  You can choose from compatible cartridges, high capacity compatible cartridges or genuine Brother cartridges from Affordable Ink.  Compatible LC436 cartridges are significantly cheaper than genuine Brother cartridges with the price of a set of cartridges being close to the price of a single genuine cartridge. The ink capacity of a compatible and a genuine cartridge are the same. 

Genuine cartridges are reliable and are likely to work every time.  Compatible cartridges are a much cheaper alternative to genuine cartridges and we guarantee the compatible LC436 cartridges will work in your Brother MFC-J4340DW printer or we will  refund your purchase price in full.