You may be thinking "what the......." Well it's true you can use a spare tyre as an air supply. You can fill them up free of charge at a petrol station but they will run out in a short amount of time which can be a real inconvenience.
These are used mostly by hobbyists and can get quiete expensive to use after time.
The bottles are filled with compessed Co2 food grade gas
available from BOC gases. You hire the bottle on a per year basis and have it refilled at an extra charge as you need to. You also need a comet regulator which you will need to purchase outright this will set you back about $130 they are available from BOC gases also.
This can be a good option to eliminate the need to always have power available.
There are a few different designs available that would be suitable
Industrial Air Compressors:
These compressors can be very reliable and a cost effective source of air supply but can be very noisy. There are ways of eliminating the extent of the noise output by having a wooden box sound proofed with a cooling fan installed for the compressor to sit inside of.
Benefit being you can run more than one airbrush at a time.
Oil Filled Silent Air Compressors:
These compressors are compact and will run on working airbrush all day long without any noise output. The disadvantage is that they have to be kept upright at all times as the oil can be spilled into the cylindar which will go up into your airlines and spoil your work.They are expensive to purchase and need regular maintenance.
Oil -less Silent Air Compressors:
These have to be the best choice available for the airbrush temporary tattoo artist or for any airbrush artist for that matter. They are portable, silent, and very durable with little to no maintenence needed. They are however the most expensive setup top buy but once purchased there is nothing else to outlay.