I hadn’t thought about marbles for many years, until these turned up in my Christmas cracker. I put them in a bowl where they have been ever since. 

Marbles always fascinate.  I love how they catch the light as I turn them in my hand and roll them around my palm.  How does the colour get inside? There are some fascinating videos on YouTube of the hand made process, and some beautiful, highly decorative marbles. But even my cracker present, mass-produced marbles are a thing of wonder- and a challenge to draw.