(a) the order in which constituents of the redox solution are added has no influence,(b) Tween 20 is an advantageous alternative to Synperonic N, and (c) maleic acid isto be preferred to malic acid during the prewash. The sequence "DFO – NIN – PD"was tested, and the results confirmed what had already been pointed out about theusefulness of using PD in terms of detection of additional marks and qualityimprovement of the already detected ones (232).TECTOPO – This lipid reagent has been used to detect marks on papers using time-resolved luminescence (233).Nile Red - Nile Red is a newly proposed fluorescent lipid stain to be used on wettedporous substrates. When compared with PD, it appeared that PD remains the mostreliable and sensitive technique. Nevertheless, Nile red can be added at the end ofthe treatment sequence for porous substrates, after PD (234).