A VFNH single of the 15c dull purple Greenland Mountains from the 1967-1973 Centennial Definitives with plastic flow variety on lf-fl paper.
Unlisted in Unitrade on this paper type. The variety is not quite as strong as some examples we have seen, but it is very clearly the plastic flow, with visible doubling of both numerals.
Unitrade values this at $150. The stamp offered here grades 84 as follows:
