Bloodhd

: The soap helps the dye lift from fibers during washing, though you should always test a small patch of fabric first. 3. "Chemical Cut" (Special Effects)

: Apply a solution of Potassium Thiocyanate to the skin (it will look clear). Trigger : Coat a blunt prop knife in Iron (III) Chloride . BloodHD

For a magic-like effect where a "cut" appears instantly on the skin: : The soap helps the dye lift from