to assure a positive test result at higher concentrations the surface of the sheet stained a uniform red color which is indicative of commercial papers containing high lignin content fibers for effective use as a security feature low levels of addition are preferred in another experiment a tmp pulp having a lignin content of about 28 was added to a standard 85 hardwood 15 softwood bleached chemical papermaking furnish at concentrations of about 0 125 or 0 25 handsheets were prepared and when spot tested with phloroglucinol stain individual tmp fibers were easily discernable when they turned red it will be noted that lower levels of addition were used in this example as compared with the previous example since the furnish in this example was a 100 softwood refiner tmp pulp which produced a more intense red coloration on each of the lignin rich fibers in order to determine the effectiveness of the staining technique on coated paper products the same tmp pulp used in the previous example was incorporated into a standard chemical bleached papermaking furnish at concentrations of 2 0 or 4 0 lbs ton handsheets were formed and a typical coating formulation containing clay and calcium carbonate was applied to the handsheets at a coat weight of about 9 0 lbs ream ream size 3300 sq ft the sheets were machine calendered two nips at 300 pli before coating and supercalendered four nips at 500 pli after coating spots tests on the coated side of the handsheets with the phloroglucinol stain showed that the tmp fibers turned red in less than 30 seconds accordingly it may be seen that an authenticatable paper product can be produced the novelty of which involves the use of only a small amount of an otherwise conventional papermaking material in a bleached.