I have fifty-four cans of spray paint. Seriously, I just went to the basement and counted. Years worth of specific projects, a couple of content campaigns with the awesome people at Krylon, and it's really become quite a collection.
And I still don't have all the colors I need. See, while spray paint is often the best tool for a specific task, your options are relatively limited. Compared to cans of wall paint, which you can get mixed in thousands of colors at the hardware store, and artist paints like oils and acrylics, the color of palette of spray paint is limited to those determined useful by the manufacturer.
I've been eyeing one of those fancy spray guns, but until this, this DIY spray paint trick from Instructables has me mighty intrigued...
"Using the spray mechanism found in standard spray cans and some common discarded items you can make your own spray paint. This project uses a bicycle pump to pressurize a small PET pop bottle, and by varying the amount of pressure you pumped into the 'can' and the types of paint added you can produce different effects. The style I got based on the paints I used and the pressure applied is reminiscent of a graffiti mop style."
DIY Spray Paint [Instructables]