Instead of dry erase markers?

Definitely recommend chinagraph pencils (grease pencils)

I was also going to recommend wet-erase markers (also known as "Vis-a-Vis Pens"), since they can be passed around and their ink won't wear off during play unless you spill something on your writing surface. They also seem to have less residue than grease pencils, in my experience.

Affordable? Not so much. But I'm not certain of your publishing goals. Publishers may have more resources.

When I was a Kid, there was a "technology" consisting of having a film of platic over a pad. You could write with any hard material on the plastic sheet which simply, stick the sheet on the pad, making the area darker, thus readable.

When you wanted to erade the whole page you simply removed the plastic sheet and place it back on the pad.

Unfortunately, as an adult, I have never seen again that "technology" anywhere anymore. I don't even know how it is called.

Exactly

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=imgres&cd=&cad=rj...

Surprisingly, I saw something else yesterday at walmart as a girl toy, which worked with a similar technique. It was oddly round shaped and translucent. But I have no clue how the erasing process worked.

That could be even more interesting, because you could place a printed sheet of paper behind the pad. Which mean if you wanted squares to write in them, you just put the square under the pad, and write on the pad. That makes the "layout" changable.

Really cool that you can INSERT pages underneath as "templates" or "stencils"... Too bad, like you say, that model does NOT ship to Canada! Very interesting indeed... You can find it on "https://www.amazon.com" using:

Boogie Board Blackboard

AMAZING freaken thing for only $39.99 USD! Can even erase portions of the board too ... Real NEAT!

Thanks for sharing... An impressive find indeed.

@Eric: You can find this product at "https://www.walmart.ca" for $59.95 CAD. I think at that price point, you may even qualify for FREE delivery. Just search for this on their online website:

Boogie Board Black Board

" that model does NOT ship to Canada! Very interesting indeed"

Apparently, there are some models at Staples (Bureau en gros), but I have not checked in store to see how they look like.

It's a shame that those things are not "Eternal". Maybe there is some ideal conservation conditions. Like, not putting it direcly in sunlight, or in heat.

Effectively, they seem to cost around 40$ CAD, so it's pretty interesting to sometime make some sketches of graphic or compute stuff. It could be usefull when programming.

Still, nothing you write is saved, so you need to make you never need to save the information you write.