  We present a numerical determination of the order-disorder interface tension,
\sod, for the two-dimensional seven-state Potts model. We find
$\sod=0.0114\pm0.0012$, in good agreement with expectations based on the
conjecture of perfect wetting. We take into account systematic effects on the
technique of our choice: the histogram method. Our measurements are performed
on rectangular lattices, so that the histograms contain identifiable plateaus.
The lattice sizes are chosen to be large compared to the physical correlation
length. Capillary wave corrections are applied to our measurements on finite
systems.
