Phil- I am not sure, maybe just to make it look good, but suspect it is to stop paint build up, by relieving the slight vacuum in the back of the cap, and just outside the nozzle (venturi effect), this would be caused by the speed/expansion of the air coming out of the nozzle - the slots would allow air to get in behind the spray plume and equalise the pressure, which would stop paint being sucked out of the plume and sticking around the sides of the cap....... clear as mud ????
You just wanted to show off your Macro photography skills, good pic. You can use them without the cap, to get close for fine lines etc, but as I am sure you know, WATCH THE NEEDLE. Also see the burrs on the slot edges, I filed these down (and the chrome) with a fine jewelers file, seemed to also cut down the paint build up.
Also - see post #22 for 'hot up tips' -
Buying new airbrush opinions wanted
Sorry for rambling, I have had a couple of wines tonight.pete
philB
