Ink a layer

I created a new layer and set the sketch layer to about 50% opacity so I could barely see the lines of the sketch underneath my new layer. I then took the Technical pen with a 90% opacity and I began to do a more detailed line drawing over the top of my own sketch. I always take my time with these lines as I need to make sure they’re quite accurate and everything is joined up, as I may need to flood fill parts at a later stage.