Nodri wrote:
I have used Flo-Aid (the standard Liquitex stuff that's found in art stores) since the first day I started painting minis. It's kept in a dropper bottle and diluted 1 part Flo-Aid to 10 parts water. Because of the dilution ratio, I've only ever bought one bottle and that was six or seven years ago. It works very well with a brush and just as well with an airbrush. In fact, it's the first thing I add to all paints to thin them (the second being generic acrylic airbrush thinner for when the paint starts to break apart and the third being slo-dri medium but that's only for cranky paints in specific circumstances). I've never noticed any problems with adhesion and it's been used on every single model I've ever painted.

The proper term for Flo-Aid is a surfactant, meaning it reduces surface tension. It makes water wetter, if that makes sense. For airbrushing purposes it makes the paint flow easier, smoother, and at lower PSI. It also reduces tip-dry. It will have zero impact upon adhesion.

Use it. It works very well and its cheap. Win-win.

 Weboflies wrote:

AllSeeingSkink wrote:
Vallejo's Flow Improver actually adds some bite to the paint, as in, it's somewhat of a solvent that gently dissolves some of the underlying paint. So no, it doesn't reduce adhesion, if anything it improves it vs. using water.

I still use Vallejo Airbrush Thinner as my primary thinner for airbrushing, but if a paint is being troublesome and not spraying smoothly, I might also add a drop of the Flow Improver.

Does this mean it's ill advised to use it with a brush? will the bite of the flow improver combined with the friction of the brush lift the paint below?

 Weboflies wrote:
That's interesting, I have some liquitex I've mixed at 10;1 and it gets really bubbly when I shake it up. I would have thought it'd get all sudsy coming out of an airbrush.