Kaleido is the brand name under which airbrush manufacturer Gaahleri offers paints, varnishes and primers. All products are acrylic and specifically developed for use with airbrushes.
These primers are available in white, light grey and black, in 60 ml or 210 ml plastic bottles.
The presentation is excellent, with an elegant box in the colour of the primer, which contains another inner box made of thicker cardboard for reinforcement and protection.
The bottles are sealed with aluminium foil under the cap, which helps to preserve them by completely isolating them from the air until first use and preventing spills during transport.
The lid is hinged, covering a central nozzle. The lid closes tightly, but the fact that the nozzle is in the centre of a flat cap, although common, is a slightly inconvenient as it makes it difficult to pour without spilling a little over the edge.
The bottle comes with an agitator ball to facilitate mixing.
The primer is quite liquid and practically odourless. To test them, I used the Gaahleri Aventus airbrush with 0.2 and 0.4 needles and my tabletop compressor without a tank.
The performance was excellent both at medium pressure with 0.4 to cover larger areas and with 0.2 and lower pressure for detailed pre-shading. No dilution was necessary. It covers very well, does not run, and a few coats are sufficient. There was almost no clog, even with the 0.2 needle and low pressure.
It is dry to the touch in a few minutes. The finish is very fine, leaving the surface perfectly smooth and matt.
After a day of drying, it can be sanded without leaving steps, in case touch-ups are necessary.
Cleaning the airbrush is easy as with any other acrylic paint, diluted with water when still liquid and removed with alcohol if dried.
Test of light grey with black shadows using my less-than-steady hand
Sanding with 400 grit does not produce steps or surface tears.
Hull re-primed on top with black, perfectly smooth and covered
Testing with the delicate details of a 1/72 figure. Note how everything remains clearly visible.
Strength tests
Physical
Adherence is strong, rubbing with brushes or fingers does not affect the primer. There are no marks or flaking. Tamiya masking take does not affect either, even when pulled roughly.
Chemical
Tested different products rubbing a large drop with a stiff brush. Water has no effect. Vallejo Airbrush thinner removes it back to bare plastic. Enamel thinner has no effect. Mr. Decal Setter has some adverse effect, changing its appearance but not dissolving it.
Note that these are resistance test on a primer, the paint you put over it will obviously get most of the effect of any product. But I think it is worth to test.
Conclusion
After using it in this test and also in other kits (these figures and the M119A2 howitzer) I have a very positive opinion of Kaleido primers. They spray easily, does not smell, self levels and dries as a thin coat that does not hide any detail. It can be used with 0,20mm and 0,40mm airbrushes without requiring specially high pressure.
A really nice Primer, available in the most common shades and easy to use straight from the bottle.