A lot of people have been talking thicknesses of their coating. It was driving me batty not knowing my actual EOM. We bought one of these guys
http://highlinemeter.com/ HighLine Meter II Paint Thickness Gauge.
It's awesome. Measures in mils and microns. I check my coating every few weeks to make sure i'm being consistent.
It's also cool to test ink thickness on a shirt once you've printed and dried it.
It was an expensive gadget.. But i'm super super happy that we bought it and use it all the time.