While the fabrics used for the main compartment are laminated and waterproof, they are sewn together. This leaves small needle holes for water to slowly seep through.
These fabrics do stop alot of water ingress compared to traditional coated fabrics and crucially don’t soak up as much moisture. When used together with a liner (or a few drybags), you get at very serviceable waterproof system.
Some pack and fabric combinations would allow seam taping but I’ve stopped offering this. A fully waterproof pack is an inviting idea but wear and tear will quickly make it lose waterproofing, necessitating a liner anyway.
