Nowadays even the humble pencil is obsolete. It's quicker and easier to do the workouts and linework on the computer.
With a little bit more time and I can put on some flat tone to liven it all up.
On this page are examples of frames with tone and frames with just the line (click on the images to view).
They're great if you have tight deadlines and you want something that looks good and is quick to do, to help sell your ideas and they can keep the price down too!
Of course you can always work them up in colour later if required.