| 摘要 |
<p>Inorganic sheets (10) of at least two surperposed layers are provided with one or more symbols (20) which have a size of between 1 and 10 νm. The inorganic sheet is made up into pigment flakes (15). The symbols on the pigment flakes (15) allow a tracing of compositions such as printing inks or paintings and of substrates carrying such compositions.</p> |
