I use Vallejo clear gloss which normally doesn't need thinning to spray through my .5 nozzle.But I bought a new bottle yesterday and tried spraying the sidewinders for my Harrier with it.It didn't work very well.So I diluted it a bit with tap water and it then worked fine.I haven't used The Humbrol one for a few years.But I used to thin it the same as their paints.Roughly 50,50 though I don't measure it.\ said:That's looking good Dave. With the gloss clear coat is it the Humbrol one if so do you dilute it? If you do what ratios do you do?I have a build I am doing at the moment and want to use some on it. Having never airbrushed with it I was wondering how best to go about it.