David's link will give you options.
This is one method to consider:
- Create the nomenclature in a sketch.
- Create a Fill feature by projecting the geometry of the note sketch.
Image may be NSFW.
Clik here to view.
Otherwise, yes, you can extrude the original sketch to create a solid.
I prefer the solid option; but be aware of accuracy issues. I also prefer to make the "silkscreen" a separate part assembled in the next level.
