Tamiya X-21 Flat Base.
This is NOT a clear coat, like Humbrol Mattcote. It is intended to mix with other Tamiya paints, to make them matt, or satin in their finish. If you do apply it direct to your model, you will get an opaque, white mess!
That said, you can mix it with Klear, to produce a matt or satin finish, depending upon how much you add. Trial and error is the general guidance here.
If you want to airbrush your Klear/X-21 mix, it makes a nice, even coat. Brush painting it may result in streaks, as you’ve thickened the Klear and it won’t self-level.
Be aware that you’ll need to run an ammonia-based product through your airbrush, to clean it of Klear and the X-21.
Tamiya TS-80 Flat Clear
This is a clear varnish, available in a spray can. It does say on the can that it is inadvisable to spray this onto ‘decals and stickers’. However, no-one has reported any problems to this Forum, although it may be advisable to brush a sealing coat of protective Klear onto your models decals first.
Humbrol now also produce spraycan varnishes and these are ideal for those of us who do not use an airbrush, but who do not wish to spoil our carefully applied weathering by brushing varnish over it.
Humbrol Varnishes vs Humbrol ‘Cotes
Humbrol has long produced Gloss, Satin and Matt enamel Varnish, (H35, H135 and H49 respectively). Many of us were brought up using these, with varying results. They are exactly like enamel paints in that they take a while to dry and you need thinners to clean your brushes after using them. One real downside is that they tend to go yellow over time.
In recent years, Humbrol have produced acrylic versions of these varnishes and these tend to be more user-friendly, in that your brushes can be washed in soap and water afterwards, just as if you’ve been using acrylic paints.
Humbrol Mattcote, Satincote and Glosscote are solvent-based varnishes that require thinners for cleaning and…er….thinning. However, current thinking remains that they do not yellow over time.
All varnishes and ‘cotes need thorough shaking and stirring and shaking and stirring again, before use. This is especially true for the matt and satin finishes, as the componant that makes the matt or satin finish separates from the solvent over time, forming a thick ‘gloop’ at the bottom of the jar or tin. If you don’t mix this thoroughly, your mattcote/varnish will give a patchy finish, probably with matt, satin and glossy areas.
Vallejo Color 520 Clear Matt Varnish
On using this stuff, Mike Williams shared his experience;
I have used their Model Air paint which is airbrush ready straight from the bottle. However they do make a their own thinners which is very good, alternatively use common or garden tap water to thin 50:50.Does it spray good? It does but needs two to three coats for a dead flat finish, can clog the airbrush.
Any problems? Airbrush clogging on occasion and thinning ratios can be hit and miss
How long to dry? touch dry in 20 mins approx. tough dry in a couple of hours, fully cured overnight. Typical of most acrylics TBH
Will it spray straight from the bottle or does it need thinning looks as if it is a bit too thick to be sprayed? yes it will need thinning, use their thinners or tap water.
What’s the coverage like? Good but needs more than one coat for proper flat/matt finish
Will it spray over FUTURE/KLEAR with out any problems? Yes
Lifecolor LC27 Matt Clear
Lifecolor matt clear is an acrylic varnish that dries perfectly flat after one application. It brushes very well, for which use it can be thinned quite adequately with water.
For airbrushing, thinning with Lifecolor's own brand thinner is highly recommended, although water or even isopropyl alcohol (IPA) can be used.
Lifecolor matt clear has the big disadvantage in that it does not respond too well to excessive handling, and will wear off quite easily. Nevertheless, it is a very useful addition
to the modellers' arsenal.