Most commericals pens do not arrive ready to be used as eyedroppers. Conversion is a possibility but sealing and ink flow problems often plague the converted pens. A lot of cartrifge pens also do not have feeds capable of buffering large amount of ink in the reservoir. Can any users recommend me beginner pens (below 50 USD) that have the ability to accomodate a converter, cartridge or ink straight from the tank? I already have ebonite eyedropper pens and also one made by Pilot. It would be good to know of a few more commercial eyedroppers.