more than likely it's dripping instead of actually ejecting out of the nozzles, so either it's picking up ink from something that is too wet (maybe the cap(s) aren't draining properly), or there are paper fibers attached to the head, or a hair, or something that can pick up wet ink and carry it across, or, worst case, it could be a seal has broken slightly on the damper assy which is causing a lack of negative pressure. It's not particularly easy to actually just LOOK at the head in that model, but if you can get a dust-free cloth under it with some printer cleaning solution (not windex) you hopefully just have a hair or some fibers travelling with the head and shaking off droplets when the head reverses course at the edge of the print--
