Where can i get ribbed aluminium or steel sheet?

[kingbob]

Got an email back from the manufacturer, apparently the spacing on this pattern is 3mm!
Should be pretty much perfect! Its available in 0.55m, 0.8mm, 0.9mm thicknesses.

I think its a rolled pattern, so the inside and outside will have the same finish. May need a little something behind it to keep it rigid, but should be good.

I'm going to ask for a pic of the profile to check, and get some pricing.