A VFNH single of the 3c scarlet from the 1932 Imperial Economic Conference Issue, BABN-m paper, showing horizontal & vertical gum breaker ridges.
The usual horizontal ridges are 5 per stamp spaced approx 4.5mm apart. Then there are vertical ridges - four from the right side, spaced approx 2.5mm apart. We have never encountered this before.
Unitrade doesn't list this variety, so we estimate it at $20. The stamp offered here grades 80 as follows:
