Primer
Without primer, the best paint will chip and flake, because aluminum has tiny holes that keep it from bonding with paints. Be sure to apply primer before painting. This is equally important if you are repainting over old paint, as some paints (particularly lacquer) will create undesired chemical reactions. In addition to providing a bondable surface, the primer protects the aluminum from rust.
Paints
Automotive paints work well for bike frames, but these sell only to professional shops and require a more skilled hand. For an accessible product that will create a uniform finish, aerosol paint cans, also known as rattle cans, are an option. They are also convenient; small with little cleanup involved. As long as you use primer, lacquer or enamel-based paints will work fine.
Quality
With rattle cans, cost corresponds directly with quality. Aerosol paints are thinner than liquid paints. Apply several coats to achieve a saturated color. This is especially true if you are working with light colors. And if the unpredictability of the process concerns you, avoid red, orange, and yellow. These are the most hit-or-miss on the bike paint color wheel.
Clear coat
Although rattle cans have clear-coat in them, the amount is usually not enough. To protect the finish, be sure to apply a clear-coat after painting. Finally, as cross-use can cause chemical reactions, always purchase your primer, paint, and clear-coat from the same line.
