A New Method for Differentiation of Skin and Core of a Rayon Filament

A new and rapid technique for staining the skin of a rayon filament and hence for determining the skin area is described. The technique requires the combined use of two dyes, Solophenyl Fast Blue Green BL. (Geigy) and Aniline Gentian Violet. It is known that the Solophenyl Blue Green dye will only stain the core of a viscose filament. Upon the addition of Gentian Violet, the blue-green dye will be removed from the core and the skin will be stained a violet color. For the test to be successful, it is necessary that the core of the filament be stained first with the blue-green dye before the violet is added to stain the skin. This technique is found to be less time consuming than the Victoria Blue technique for selective skin dyeing as described by Morehead and Sisson [2] or the selective staining of the skin described by P. H. Hermans [1]. It is probable that only physical absorption of the dyes by the skin and core is involved.