That's a great and very practical question! Dealing with a torn bag inside a rough, plastic urban trash can is a messy and frustrating problem. The good news is, with a few key considerations, you can easily find a liner that holds up.
First, focus on material and thickness. Look for bags marketed as "heavy duty," "contractor," or "extra strong." The thickness is often measured in "mils" (thousandths of an inch). For a rough interior, aim for bags that are at least 1.0 mil or thicker. High-density polyethylene (HDPE) bags are stiffer and good for sharp debris, while low-density polyethylene (LDPE) bags are more stretchy and puncture-resistant.
Puncture and tear resistance is crucial. Keywords like "puncture-proof," "armor shield," or "diamond weave" technology indicate the bag is designed to withstand abrasion from rough surfaces and sharp trash edges.
Fit is equally important. A bag that's too large will sag and be more likely to catch and tear on the can's rough edges. One that's too small will be overstretched. Measure your can's height and circumference to find a well-fitting size. Drawstring bags can help secure the liner and keep it from sliding down into the can, where the rough plastic can grind against it.
Finally, consider the can itself. If the interior has particularly sharp seams or molded textures, you might gently sand down the roughest spots with fine sandpaper. Alternatively, using a slightly flexible, smaller plastic bin (like a cheap bucket) inside the large can as a buffer can protect your liner.
In short, your best bet is a thick, puncture-resistant, properly sized heavy-duty bag. It might cost a bit more, but it saves you from the hassle and mess of a cleanup.