many times micron pens are stated as supplies to use for embroidery because you can get a fine tip pen- they do not bleed (fuzz around the edges) and it is (assumed) your embroidery thread will cover them. if you would prefer a marking tool which will wash out there are tons to choose from- i love the fine tip marking pencils with the ceramic leads- fons & porter, dritz & sew line all have ones out- the leads are fine -thin, i've found them in pink, green, white & lead colors- and they wash out- or are erasable. i tend to stick to pencils or chalk for most of my marking-regardless of whether it's for embroidery, quilting or tracing appliques- i've just had the best luck with pencils-
i've over the years spent money on this (disappearing ink) marker - or that one- generally they seem like a waste of money-to me- they either dry out long before i think i've got my fair share of marking out of them- or they don't come out as well as i thought they would- so i don't tend to spend money on markers if i want the marks to come out.