Felt tip pens with magic ink, water-based, solvent-free. Conform to European Safety Standards for Toys (EN 71)
For painting, drawing and writing on paper surfaces. Firstly paint with one of the color pens, then paint with the white pen over the colored area and the color will change
For "cryptographs" write at first with the white pen - then decrypt with one of the color pens
Cap of the pen shows the original color; the round inlay of the cap shows the changed color after application of the white pen