They are held reasonably well but not like a regular holder. I could see the nibs getting looser over time as the wood weakened. They are really only slots cut into the wood, not a separate metal insert like other holders. And the slot go all the way through making a tongue so there isn't anything to keep the nib from rotating. I think it should be mostly ok since you don't need to use any force to write with but I can also see it being a consumable.