Polycarbonate is the most popular shell material for good reason — it offers an excellent balance of weight and durability that suits most skiers and snowboarders. It's used in in-mold construction, where the shell and foam liner are fused together, resulting in a lighter helmet than traditional hardshell designs.
For everyday resort skiing, polycarbonate holds up well to normal wear and tear. It provides adequate protection and meets the same safety certifications as helmets with other shell materials. The main trade-off is that it can show scratches or dents more easily than tougher ABS shells if you take a hard impact or toss your helmet around carelessly.
If you're a budget-conscious buyer or tend to be rough on gear (like kids or rental fleets), ABS might make more sense. But for most riders who want a comfortable, lightweight helmet they'll actually want to wear all day, polycarbonate is the way to go. Just don't assume a pricier carbon fiber shell is safer — all certified helmets meet the same impact standards regardless of shell material.