Smudges and smears on the page
Marks on the back of the sheet or along the edges mean ink has reached the rollers, and there's usually a clean page or clean paper path routine in the printer's maintenance menu for exactly that. Run it a couple of times with plain paper loaded. If the smearing is in the printed area itself, you're probably printing at a photo setting on plain paper so the ink has nowhere to go, or the paper is slightly damp.