Certain stationery implements seem to be able to communicate a sense of fun and joy – they make us smile and beckon us to make use of their potential.
I think the Mateo Ilasco Numbers Notepad does this.
There are thirty-two numbered lines, each connecting back via another line to some groups they belong to – composite, odd, even, prime.
More graphic design than math, the paper is very interesting and provocative. It has a generous blank top area, and a substantial heft.