To know how this work, check my instagram video:
https://www.instagram.com/p/CsZGty_AN8S/
You need a glass plate (I use an old photo frame glass). The model can fit only 18.2*13.5cm (+-0.3cm). Thickness: 3mm
You can scale or modify it for other dimensions.
This could works also with a plastic plate of the same measures.