Washable markers for NP program lab?

[AtomicWoman]

I am a student in an Adult NP program. We were told to bring "washable markers" to lab because we are going to be labelling each other's thorax! Does anyone know of a marker that is truly washable? Do the Crayola markers work? Sorry if this question seems off the wall!

[CRF250Xpert]

I took 3 assessment classes of the years and never heard of using markers on a fellow student. Are you talking about simple diphramatic excursion and liver borders? Plain ole ball point pen works fine, but purple skin marker is the proper tool if you want to split hairs since it wipes off with an alcohol prep pad. There's no drawing, just a dot.