Our NCT Nano Backpack features our signature Nano Cure Tech Fabric. NCT is lightweight, waterproof nylon ripstop with resealing and repairing capabilities. Naturally, nylon rip stop is extremely durable, but when combined with the the special double sided coating and the heat of your fingers, small holes and punctures can be repaired. The healing effect works very well on small punctures or lacerations which means we certainly don't recommend testing your new backpack with big scissors or knifes, but who would?