You're almost ready to get started. But first, you'll need these items:
Firstly you will need to transfer some linseed oil to a glass jar. Place your charcoal in the jar with the linseed oil and let it steep overnight.
Remove the charcoal from the jar once it has had time to steep and remove any excess oil using a paper towel. You can also wrap some aluminium foil around the end of the charcoal stick to make it easier to handle.
You will notice that the charcoal has transformed into a very dense drawing material. When tested on oil colour paper it is noticeably more intense than regular charcoal and has a more stable stroke. Whereas traditional charcoal is easily wiped from the surface of the paper, the oiled charcoal is much harder to remove; the lines are much deeper and darker.
It is important that you use the oiled charcoal quickly. Once the linseed oil has dried into the charcoal, it will make it too hard to draw with effectively.