WHAT are you painting ? Do you know how lethal automotive spray paint is ?!!! It's about as carthenogenic (sp ?) as playing with mercury or lead !!! You inhale about a minute of it, and you can go into cardiac arrest, collapse, and die !! You should read the WHMS labels for the paint and it's components. You HAVE to use an approved respirator or else you face very very scary consequences.
When you mix automotive paint, you have base paint, which consists of pigments, fillers and stuff, but it's the hardender or accellerator that will kill you.
You do NOT play with this kind of paint vs spray paint you buy off the shelf.
If you are intending to put it into a small sprayer (the kind with the glass jar, and it's own propellant), you will NOT get the same gloss you achieve with a commercial spray gun. You need air pressure around 25-40 psi on a proper gravity feed or suction gun to achieve gloss.
Not sure what you are intending to paint, but for what it's worth, take it to a shop, and have them blend up the colour in-house, and spray it. PLUS, you need to make sure you have the parts completely dust free, cleaned ultra clean with tumbler, properly scuffed, and proper type of primer layed down first...with adhesion promotors and or flex agent for plastic or rubber parts.
ps...I don't work in a shop, but have sprayed probably 4-5 complete cars in the past 5 years, so I'm around bodyshops a lot.