The Straight upnosed gouge is specially made for making troughs. It has got a slightly longer handle and the blade is made in a fishtail design. This gives it low weight and better overview.
The bevel shape is expressed in a diameter (mm) and an approximate width (mm). The bevel shape is part of a full circle. The number that the gouge is marked with is the diameter of this circle. The width is measured across the gouge.
Using a gouge with a more convex bevel shape makes it easier to remove material, therefore they are perfect to start off a project with. The flatter bevel shape is better for smoother carving, therefore a better use at the end of your project. A flatter shape demands more strength, since it makes wider wood chips. It is advantageous to use many different shapes of gouges during your project.