A concave, convex or twisting change of form, used to describe stiff organic materials that have become misshapen, such as paper, card, plant fibres and wood.
![](https://aiccm.org.au/wp-content/uploads/2019/10/web.distortionIMG_1843.jpg)
A concave, convex or twisting change of form, used to describe stiff organic materials that have become misshapen, such as paper, card, plant fibres and wood.