| abstract |
A product (20) for use on a surface or as part of a surface, the product comprising: a first layer (22) which carries an indication; and a second layer (26) which overlies at least a portion of the first layer (22), the second layer (26) comprising a porous polymer; wherein the second layer (26) is opaque when dry such that the indication is masked and transparent when wet such that the indication is revealed. |