Ok hear me out. I only remember one detail but it has randomly popped into my mind and I remember being so taken with it at the time.
Not a picture book, a chapter book aimed at older kids I think. The detail is that the kid in the book gets their hands on an unused roll of wallpaper, and uses it to draw on the back of.
Not just scribbling, I think it was a cohesive design that ran continuously across the paper, possibly a town scape?
I think new pens and pencils were involved.
That's it. Anyone?