How to set/seal waterbased paints

I'm using TAG to do a full body lavender color for a cosplay. I have read that powder is not necessary for water based, but I've also read that powder is useful for bodies.

There are excellent sealants to use for body painting with water-based paint.

With Blue Marble SeLr, spray the body lightly and evenly first, avoiding the eyes.
Use your wax based TAG paint with either brush or sponge.
Once dry, evenly top coat with the Blue Marble SeLr. The top coating tends to 'fuzz' the linework. I can touch it up easily.

Kryolan sells a fixing spray, and it is expensive, considering how fast it runs out.

I have used Blue Marble SeLr at Fantasy Fest in Key West. It is humid. It rains. People sweat. The SeLr really keeps the makeup in place.

The facepaintforumshop.com also sells alcohol hybrid body paint called ProAiir. ProAiir can be airbrushed, or sponged on. ProAiir does not need a primer coat, or sealant. It is water proof.