That's a great question, and one that's very relevant for public spaces, parks, or urban areas. From my experience and research, stainless steel outdoor trash bins actually hold up remarkably well against graffiti, and they're often a top choice for this very reason.
The primary advantage is the non-porous surface. Unlike painted metal, wood, or plastic, stainless steel doesn't absorb spray paint or markers. The graffiti mostly sits on top of the surface. This makes removal significantly easier. Maintenance crews typically use a specialized graffiti remover solvent or even a mild citrus-based cleaner and a rag or non-abrasive pad. Often, the graffiti wipes right off without damaging the underlying metal.
Furthermore, high-quality stainless steel bins, especially those with a brushed or satin finish, are excellent at hiding minor scratches and scuffs that might accompany a graffiti cleaning attempt. A polished finish might show marks more easily, but it's still very cleanable.
Their durability is the other key factor. They won't rust or degrade from harsh chemical cleaners needed for removal. While determined vandals with sharp tools can still scratch them, the surface itself is tough and doesn't peel or chip like a coating would.
So, to sum it up: stainless steel bins are one of the most graffiti-resistant options available. They don't prevent graffiti from happening, but they make the cleanup process fast, effective, and cost-efficient, ensuring the bin looks good for years with proper care. For any space concerned with vandalism, they are a very smart, low-maintenance investment.