Lightweight nylon (100D–200D) ski backpacks can shave serious ounces off your setup, which matters on long uphill laps or ski mountaineering races where every gram counts. If you're the type of rider who obsesses over weight and moves fast in the backcountry, this material is a legitimate choice.
The tradeoff is durability. Low-denier nylon has much less abrasion resistance than midweight or heavy-duty options, and ski edges are the biggest threat. One careless moment strapping sharp metal to your pack can slice or puncture the fabric. You'll need to be deliberate about how you carry your skis and avoid tossing the pack on rocky surfaces.
For most regular backcountry skiers, the weight savings aren't worth the fragility—midweight nylon (200D–400D) hits a better balance. But if you're racing, doing fast-and-light missions, and willing to handle your gear carefully, a lightweight pack can be a great tool. Just look for reinforced bottom panels if the pack offers them.