I see within current forum questions (Visitor nevnevsp) that molybdenum disulfide has been used at 4.2K as a lubricant. Does this work well i.e. provide good slip between otherwise solid surfaces which are in compression? If so does graphite and PTFE also convey the same lubricious properties at 4.2K. Would an 8B pencil work at 4.2K? Or has any one tried writing with a such a soft pencil with the lead under liquid nitrogen which may be a more tractable experient?