With Derwent Inktense Pencils, you can achieve the intense colours and translucent effects youd expect in a pen-and-ink drawing with an easy-to-control pencil.
You draw with them just as you would a traditional pencil, then wash over them with water to leave an ink-like effect.
This is permanent once dry, so you can use other media on top to create an almost limitless range of effects.
Theres also a non-soluble outliner for drawing permanent outlines that wont be affected by water.
As well as paper, you can use Inktense pencils on fabric, and theyre particularly stunning on silk. 
They come in a range of 71 jewel-like, highly blendable colours.