[Austin W Hogan]

I have had the opportunity to examine some engraving close up, using microphotographs. As I remember, the 16 ga Invincible had about 30000 engraving strokes per square inch, and the frame was completely covered; a "full canvas" as Geoffroy says.
There is a lot of "empty canvas" on that floor plate, and little relief or shading when compared to the dog on the side of the frame. The time spent depends on the individual engraver; but there are more strokes on the sides of the frame than the floorplate.

Best, Austin