What type of aluminum can be anodized?

[luke]

6061?

[cooldude]

i think every kind

[Spaceman613]

every kind can be annodized, but some look rather bad. 6061 is the best for cosmetic anno.

and if you mix types of al, then the colors wont match. If you are buying billet, or raw stock, buy 6061-t6, its good stuff (unless you need some special properties).

[soilent green]

some aluminum alloys don't ano very well so be careful any one that is close to pure Al is good

[ShinyGuy]

If you want pretty colours you want 6061. It's a good general purpose Al. If you're trying to get a really hard, durable finish 2000 series Al will give you a good result. You can anodize just about any type of aluminum (and magnesium) with varying results.