Ronseal RSLGPBWH15 One Coat Grout Pen Brilliant White 15ml Need to touch up painted or discoloured grout? The Ronseal One Coat Grout Pen quickly and easily transforms the surface giving a durable and waterproof finish in one coat. So now theres no need to re-grout. Colour: Brilliant White. Available in Two Sizes (ml). Areas of use: Interior tiles. Approx number of coats: 1. Application: Pen. Drying time Approx: 24 hours. Protection level: Medium. This Ronseal RSLGPBWH15 is a 15ml Pen with re-sealable lid