For whatever reason, my character level tends to lag behind the level of the zone I'm in (for example, I just started V9 Al'Akir and I'm almost V8). The mining nodes, crates/barrels, wood, etc all give materials appropriate for the zone, but when I kill a beast the hide that drops is for my level, not the zone level. I have the skill maxed out so I can use any hide to create armor, so that's not the issue. The effect of this possible issue is I can't pregather the materials for making the appropriate level armor when I'm about to cross the cusp - like, I couldn't make V6-V8 armor until I had been a V6 for a while and had gathered sufficient materials to start crafting, since as a V5 in a V6 zone I couldn't gather Superb Hide.
I'm not sure if this is by design, but doesn't go along with all the other materials being appropriate for the zone level.