fiber v annulus m 3 u00f7 density of cell wall 1 5 u00d7 10 9 lbs 7 5 10 13 tons commercial timbers of the united states 1940 p 52 step 4 calculate amount of lumen loaded material in paperboard equ2 u2022 u concentration of loaded fobers in paperboard in ppm u2022 z 1 amount of lumen loaded matial in paperboard in lbs ton u2022 z 2 concentration of lumen loaded material in paperboard in ppm typically dyed lumen loaded wood fibers are added to the furnish such that they make up a small percentage of the total furnish this percentage may be as low as a few parts per billion on up to 20 25 in the preferred embodiment the individual lumen loaded wood fibers will be recognizable under ultraviolet light or infrared light after the dyed lumen loaded wood fibers are uniformly dispersed into the furnish it is formed into anti counterfeit paper by conventional papermaking operations the following example was prepared using the concepts of the present invention fibers were loaded with various soluble fluorescent agents these agents were each dissolved into a solvent such as methanol at a concentration of 0 5 g l 1 g l.