2 Straights

Please have a look at the other lettering videos on Woodcarving Workshops for more and perhaps fuller demonstrations of the basic chisel technique. 

The important thing to grasp here, and really for all lettering, is that the drawn lines, accurate though they may be, are only a guide. It's the cut edge which is the final decider. Working on a curved surface with a straight chisel needs a careful eye. 

When you think you're done, change the lighting and check the edges.