Depends on what you are trying to paint. And how you important the end result is to you. Big area of coverage, or small area? For a big area a gun is best as you can control amount of paint and adjust spray fan. Smaller item can be covered easier with a can. Another thing is that spray cans tend to spray dry, that is less thinning agent . They tend to hit and stick not flow together . Not impossible to do, but harder to get a good job especially on big areas. With a gun you can adjust the amount of thinner to suit your needs. Makes it easier(after you get used to it) to do a more in depth shinier looking job with more consistent coverage.