A discussion on BCUK has posed a question;

SilverHill forge has noticed that the fabric that his Maccat is made from seems less stretchy than his DD polyester tarp
Why does the Maccat ripstop tarp feel less stretchy than the Polyester DD tarp?

Its common knowledge that polyester has less stretch than nylon, so why does the maccat perform differently?

Is it the impregnation of the nylon that changes the materials properties or is it the grid?