I'm looking for a recommendation for a Matt varnish spray.

I have used the GW purity seal and found it left a white residue regardless of spraying conditions (admittedly that was about two years ago so it may be better now) and since then I've been using Humbrol hobby and craft spray varnish which is good and doesn't leave any residue but does have tendency to slightly dull blacks - gives them an almost charcoal grey appearance, which hasn't bothered me too much up until now.

I'm in the process of painting a FW chaplain dread and needless to say, dulled black is certainly not something minor for this model.

So I was hoping someone could recommend a good clear spray varnish which doesn't frost the colours at all??