I am using the markers: called Rose Labels (wires and plates) style E for my roses, ferns, hostas, and daylilies so far. I used a #2 pencil and a carpenter's pencil on the first ones and those did not show up quite as well as I would like. So this time I ordered the mechanical pencil and refills, which seems strange but is a bolder broader marker than a normal pencil. I guess it just seems strange to me because when I used a mechanical pencil it always had fine lead.
So far the system is doing the job, the critters are not digging them up and moving them around, that was the main reason for me to go to these types of labels. Somedays I like seeing the markers, but with the daylilies there are so many so close together it becomes a little distracting to me. So I plan to try pushing them all the way down near the ground and seeing how that looks. With the other plants they are spaced out more, so it is not quite so blatant. One day I hope to go to the computer printout labels, those look more attractive to me, but I am trying to garden as economically as I can. I still use a lot of the vinyl blind labels also a #2 pencil seems to do fine for me on those.