The accurate flux calibration of the ISO instruments relies on our
knowledge about the atmosphere models of stellar standard candles,
but the accurate knowledge of these models in turn relies on the
high-spectral-resolution observations of these stars, which precisely
require ISO.  Clearly, then, the final ISO-SWS calibration will result
from an iterative process involving both observations of standard stars
and interpretation in terms of stellar-atmosphere models.
This process will benefit both to the general community interested in a
good calibration and to the subcommunity interested in understanding
stellar atmosphere models in detail.
We propose to obtain full-resolution SWS full scans of a few selected
standard stars, with the purpose of assessing in detail which are the
atomic and molecular features for which an improvement of the models
is necessary, and then will contribute to this improvement.