I've been considering materials for an outdoor piece and wanted to make sure I haven't overlooked any possibilities. As of yet I have considered bronze, polished stainless steel, a sanded swirl pattern on stainless steel, painted steel or stainless, and rusting steel/corten. I've been reading about electropolished stainless, but don't know much about it. I really like the look of blackened and distressed steel, can you do this to stainless steel? Do any of you all have any other suggestions or comments about the above possibilities? Is aluminum an option? It seems kind of soft and would scratch easily?