Heidelberg Atomiser - Spray Diffuser
The mouth atomiser is a device that can be used to spray watercolour paint, ink or other liquids evenly over a surface.
The mouth atomiser consists of two hinged tubes, one of which is placed into the liquid to be sprayed and the other which is blown into by mouth.
Learning to use the atomiser is a matter of practice and of blowing hard enough to create a venturi effect between the tubes. This draws the liquid up the long tube and then propels it forward so that it sprays the desired surface.