I know antibodies clump the antigens but when does that happen? are they produced before the phagocytes engulf the pathogen, after or during?

hi!

the antibodies are the third line of defence for the human body while phagocytes are the second line of defence.

antibodies are produced by lymphocytes and attack antigens on the surface of pathogens after they pass through the second line of defence.

so the answer is after the phagocytes engulf pathogens and only if the pathogens pass through the second line of defence (phagocytes).