The real thing is sold on another page.
https://miniaturepopup.com/products/miniature-book-kit
A Mother Goose [Mother Goose] 25x32x5mm
B Secret flower garden [The Secret Garden] 20x25x8mm
C Pinocchio [Pinocchio] 17x20x7mm
D Red Riding Hood [Little Red Riding Hood] 11x15x5mm
Simple process just to fold.
The real kit is offset printing, so it won't be wet.
Aging is possible to soak in coffee.
Tools to prepare yourself
1. Cutter
2. Tools to attach folds
(Naildot pens, ballpoint pens that have stopped appearing, etc.)
3. Stick glue
4. ruler
5. Mat
6. toothpick
7. Pens, etc. (for aging processing)