With little notice, I contacted the seller for information. They responded to me within 24 hours which thus relieved me if you have any questions, please send them a mail. Short pass, regarding the product itself, it is ultimately a good product. I have used it on many surfaces (glass, plastic, etc.) and no worries, it fades pretty easily if you take a damp cloth. Ditto if you have them on the fingers so you can let your children use. Really happy with my purchase