That's an excellent and very practical question for urban management. Graffiti on public trash bins is a common issue that affects aesthetics and maintenance costs. Fortunately, several effective strategies and products can make bins much more difficult to vandalize.
The primary approach involves material selection and special coatings. Bins made from stainless steel, especially with a brushed or textured finish, are naturally less inviting for graffiti as markers and paint don't adhere well and are easier to clean. The most common solution is applying anti-graffiti coatings. These are typically clear, protective films (sacrificial or permanent) that create a barrier. Permanent coatings allow for easy removal of spray paint with specific solvents without damaging the bin's surface, while sacrificial coatings are removed and reapplied after cleaning.
Design also plays a key role. Opting for bins with smooth, curved surfaces and minimal flat, inviting panels reduces the "canvas" effect. Darker colors or patterned finishes can also help disguise attempted marks. For a more advanced solution, consider powder-coated steel bins. The powder coat is a very tough finish that is more resistant to adhesion than standard paint, and graffiti can often be pressure-washed off.
In summary, your best bets are: 1) Stainless steel bins with a textured finish, 2) Bins treated with a professional anti-graffiti clear coat, and 3) Designs with curved, non-flat surfaces. These solutions significantly deter graffiti, reduce long-term maintenance, and help keep public spaces looking clean.