My little nephews.

My brother and sister both have a son. They are more or less the same age and since they are born I'm thinking about turning them into drawings.
Look at this picture and you'll understand why.



I've worked with them fully digital.





Did some handwork in brush and ink with colors in photoshop.



And a test in acrylics and water.



Which is a detail of this sketch.



Can't decide how to continue.
Any suggestions?