I thought that they would be ideal for KOW multibasing and so ordered a couple from the manufacturer, Green Stuff World. They are a Spanish company. You can check out their website here.
The site is very easy to navigate, utilises PayPal and provides all manner of hobby supplies. Postage is very reasonable and the delivery time was 10 days (from point of order) to literally the other side of the world.
I purchased two TRPs - "Temple" and "Cobblestone". I am harbouring thoughts of converting my rats from single to multibases. They will also be great for basing of terrain pieces.
The TRPs are exactly that - textured rolling pins - and are made of a solid acrylic, so they should last indefinitely.
There is a very helpful video tutorial on how to use them here
Now I've just got to find an economical source of green stuff - any suggestions?