So after years and years of gathering up courage to make a flexible terrain mat I finally did it. My partner in crime Erik and I finally decided to just jump in and do it.
I started out with making my own flock in various shades.
Then a sheet was laid out in Eriks basement. We mixed two paint samples some sand and 6 (I think) tubes of acrylic caulk in a bucket smeared it out over the sheet and dropped the various shades of flock on it ending up with this.
I am very happy with our result. We were aiming at a sort of southern Italy/Greece kind of look. Now we are just waiting for it to dry completely so we can shake of the excess flock and see the final result.
All in all it took waaay shorter than I had imagined and was waaaay less messy than I had feared.