Here are some samples of materials with different textures that could potentially be used to fill the element:
- Soft and uneven filling (ex. crumpled paper or fabric)
- Hard and movable filling (ex. small beads or balls)
- Formable filling (ex. play dough or modeling clay)
- Formable and smooth filling (ex. slime or putty)
The user can test squeezing and manipulating the samples to get a sense of the different tactile experiences before deciding which type of filling might be most comfortable or stimulating. The element could then be customized based on her preferences.
Does this help provide some options to consider for the filling? Let me know if you have any other questions!