Marking logs with paint, where the color is the code, is one of the oldest and also low cost methods (Dukstra et.al. 2003). The marking can be completed automatically or by hand and is comparable to punching. Medium in reliability, it provides information, not log origin. Can give false readings if paint degrades or reacts similarly there are problems in marking with paint in wet log-end, with snow and mud and change of color. It is practical as there is no need for specific training. The aim is to find a cost-efficient solution. For this reason LNP (Luminescent Nano Particles) is used. These nano particles are added to the fluid paint, that becomes unseen in regular light, but when illuminated by a laser it becomes visible. The major advantage is the enlarged frequency range and the detail that the wavelengths can be alienated with high accuracy, meaning further unique identities. Additional significant findings are that LNP is more insolent to snow and mud and it is more difficult to fake (IK EU, 2010).