This issue seems to affect Monks now. Varnish does not add damage.
Can you be more specific? Does the varnish affect the gloves at all? I'd need screenshots if possible.
This has been true for a while.
Found the problem. Will fix in my next update.
When the varnish is applied, nothing happens at all except the varnish is consumed. I tried it with multiple varnishes on multiple sets of gloves multiple times over the past month.
It is a big handicap to a class that has no other way of buffing its weapon.