"I know the number of people who might care about this are few but.." ...but there are 90 replies. :) Yes, I know they're mostly from the same people... I'd noticed this myself while nosing around in OBJ files, but never thought about it as a performance problem. Thanks to all involved. I notice that John Wind's Compose utility, which I use a lot, orders groups when saving to OBJ, so that doesn't really help any. Looks like STOMP is going to be a part of my workflow from now on!