We have been using the Allflex for years with the felt tip. Pen went dry the other day and bought a Y Flex. It didn't work well at all. Long story short, tried two or three YFlex pens before we found another AllFlex. Guess it was just a bad batch of YFlex pens cause I think they are basically the same thing. As others said, lay it on thick, lie flat to dry for a few minutes to dry,and it lasts pretty long time. Never tried the Ritchey someone mentioned, but that sounds like a good system.