Wall Decals printed on high end HP latex printing machine with latex inks, which is a water-based ink, odorless, non-toxic. Decals and wallpapers printed with latex ink are safe for nurseries, hospitals, and schools. HP Latex Inks have qualified for certifications that demonstrate they meet some of the worlds most rigorous and comprehensive standards for low chemical emissions into indoor air. Designs are printed on a high quality self adhesive sticker which is easy to apply to any flat & clean surface. As each design is cut through its own contour, you can apply each one of them separately. Just peel and stick. Decal is removable and re-usable. Leaves no residue.