So I went searching for flat coat choices to both protect the miniatures and make them look realistic. The popular choice seems to be Testor's Dullcote. As a lacquer there are some concerns about it yellowing over time. Other people recommended PollyScale Flat and something similar from Model Master. The lacquer based sealers use a thinner that can be harsh on acrylic paints, especially silver apparently, which is a bit of a concern.
Unexpectedly my searching turned up a technique based on Future (known as Pledge here). The idea is to mix a matt medium, such as Tamiya X-21 (get it from Toyworld) to make the normally glossy Pledge flatter, leaving a tough, flat finish. Remember that despite all this modelling fun, Pledge is meant to be tough enough to be walked on.
A number of different finishes are possible, just my varying the amount of flat base used:
- dead-flat: 1 part X-21, 3 parts Pledge
- flat: 1 part X-21, 10 parts Pledge
- satin: 1 part X-21, 15 parts Pledge
- gloss: Pledge (what else :)
For reference here are some links:
The Complete Future - a great reference. Includes an image of the bottle (centre bottle).
Future Floor Wash - as used by a railroad modeller.