I have now added filter to the tank. I used another AK Interactive product, blue for Panzer grey. I've never used this before so it's been a trial for me. I applied the filter straight onto the paint, in hindsight perhaps a satin varnish would have been better sprayed onto the paintwork prior to the filter. I found it a bit too dark and thought it was going to be a disaster. However i slowly worked away with it and managed to control the filter. I was still a bit sceptical once it was added but after a period of drying, it looks ok and the modulated colours still come through, so not as bad as i thought! i will definitely use a satin coat the next time. It will aid the flow of the filter and better control it. You live and learn.