I already knew these pens and I knew very well that they were writing, they slide on their own which is very pleasant and does not hurt the hand saw they are super light. My only regret in this purchase is that the dark brown, a color so that I would have liked to use it (it's not as if it was yellow, which is not seen on the white paper) in life everyday, had a normal mine. His face is like jagged scratches on paper and therefore impossible to use it, but once it's written very thick and suddenly there's nothing ... Too bad for the price of the lot!