NR foam, RG 130/160 (approx. 0.13 - 0.16 g/cm³), large pored, open-cell
stamp moistener
Sponge rubber is a blown spongy-porous open-celled rubber which is produced from natural rubber (NR). Its good compressibility and elasticity, its ability to absorb and its surface adhesion all combine to guarantee that this oldest of all the blown rubber materials still finds many uses today. Not only the universally familiar stamp moistener is made out of foam rubber mats but also floats used in the plastering of walls and much more. Their intense colour and interesting surface texture have meant that the mats would inevitably be used decoratively or as a design material with many possibilities.
