Varnish

It's an interesting challenge to try to illustrate the square of varnish on R194 and its siblings, but here's a go at it.

The varnish square is roughly 15 mm on a side, and can be seen easily when holding the stamp at an angle to the light. On the one below, it shows up (at least on my monitor) as a yellowish tint on the stamp.

Although I didn't manage to make the outline quite square, here is where to look for it on the copy above.