Dragon bile purple is a grease-soluble dye, which has a special effect on the appearance of fingerprints on viscose surface. Dip the adhesive surface into the dragon bile purple solution, or point the solution on the adhesive surface with a straw,2Rinse the excess dragon bile purple solution with water after minutes. The grease content in the fingerprint is dyed dark purple.
502The processed fingerprints can be dyed into dark purple with dragon bile purple, which does not require a special light source to stimulate fluorescence.