I have Testor's Dullcote spray and also some modelmaster clear flat coat (when I bought it I thought this is the dull coat stuff). I sprayed a layer of clear flat over my model and I didn't see much of a difference from it, so then I used my spray can Dullcote and put a nice layer of that stuff on it, however my model still shines. Any ideas?

Dullcoat if not shaken properly will not leave a dead flat finish That is why I use MM acrylic flat shot through my airbrush Also sometimes if the temperature is cool enough the flat won't dry flat

giving more than one layer fixed the problem for me.

Frank