Interestingly, both of these had a common problem. They had both created lovely artefacts, with the intention that people would write, sketch or scribble on them, only to find that some people were put off. The paper products were 'too good to spoil'.
There were a few suggested solutions to this problem. One being to get people to make a very simple 'first mark' (like a cross or a dot), so that the paper was no longer pristine. Another was to redesign the packaging to make the paper feel more ephemeral.
Of course, a more fundamental problem people usually feel far more comfortable consuming a product passively – reading, watching, listening – than they do when having some sort of active involvement, however small that might be. Getting over this requires great design, lots of testing, the right prompts, and dozens of other factors.
One cultural reference in this area that I re-remember every few years is the Anti-Colouring Book. I had it as a child, and I remember it having an extensive academic introduction bemoaning the 'colour within the lines' behaviour encouraged in most colouring books. Instead, the book contained pages of 'ideas' for scribbles, all of which had been 'started', but with plenty of space left for you to continue the drawing.
A bit childish perhaps, but perhaps there's something there that other products could return to?