Chubby helpling for playbooks.
The new material made of foam could be a good help, if you want to make a book of thin felt or want to create three-dimensional effects.
It’s about 4mm thick. (I placed a pencil next to it), really sturdy and still soft.
It can be sewn in between pages in order to stabilise. It works really well.
Its called Style Vil made by Vlieseline and its available by the meter in well-known online stores.