And particularly this image since both hubby and me are electrical engineers. Circuit diagrams and the memories associated with them :)
Image colored with copics. Loved playing with sentiment danger high voltage.
If you want to learn coloring using copics or pencils do check out kitandclowder .
Either their techniques classes or monthly classes. One of the monthly classes had as a freebie class coloring metals and also timber. You can also join the FB group and get lots of inspiration. ALyce Keegan is so helpful and wonderful.