Testors Dullcote Lacquer
I have been using the bottled Testors Dullcote Lacquer with great success. This stuff along with the spray can version is excellent. The finish is truly dead matt.
If you have smaller items for basing, etc then use the bottled Dullcote it goes on dead matt and dries within seconds. It also saves on the more expensive spray can version. Also use it to touch up the finish after spraying.
You can purchase Testors Dullcote in spray cans and bottles from Antenociti’s Workshop in the UK.