[NTG-context] small smaller and vertical stretch

Hi, using "small" and "medium" rather than "8pt" or "10pt" gives some vertical "stretch". Very useful in some situations: \setupinterlinespace[small] \setupwhitespace[medium] But what to do if "small" is still too big? And yet the "stretch" is needed? While I can say ... \blank[.75*medium] ... this operation is not allowed for the two above. So, what to do? Steffen