Plates?

I have an almost 14 month old and we still just lay out most of his food on the high chair tray. I'm wondering when I should start using plates with him? For that matter, utensils too. He eats pretty well off a spoon, and I've let him practice with it before but he makes a huge mess - such is life! I'm just worried he will chuck the plate and all the food will wind up on the floor at one time, rather then him throwing bits and pieces on the floor as he sees fit.