Approx. A4 in size, conte.
By the way, the ref image is by Muralidharan Alagar, modeled by his friend Sumit, taken on the occasion of an art camp at the Cholamandal Artists' Village, Chennai.
It was mid- to late-afternoon. I had just finished the portrait above, which was then posted online, immediately following which the query was made. I wanted to demonstrate the versatility of the 'used' conte stick and took its picture. Then I proceeded to draw the ear sketch (posted further below). When used with a soft enough hand, and after you have got it shaped in that way (following a period of use), the stick is wonderfully versatile in producing a wide variety of marks - both in line depth and line thickness/width. I'll elaborate further..
Look at the many micro facets on its surface, the very sharp and pointy tip, and the knife-like edge that's extending down from it. Remember paleolithic tools used by cavemen? Those sharp-tipped, multi-faceted stones they used as arrows and knives? Well, this conte has become like a softer version of those (with me being the caveman in my studio-cave :D).
Thanks so much for viewing/reading.