Yes, mainly for see-through pens.Side question what designs are you using a bottoming tap for? Most of my cap design all worked fine with a plug. Is it for see through acrylic? Please advise, depending on the answers I may pick up some bottoming taps as well.
See the detailed comments by user Curly in this thread: http://www.penturners.org/forum/f30/taps-kit-less-pens-caps-149074/