Gill Bostock: Tampa, FL. (17th May 2003) "Dyebrick was ideal for enhancing the grout on our stone block driveway, we used a blend of Charcoal with Brown. The product was both easy to mix and apply." Note: We don't usually recommend our products for surfaces used by vehicular traffic, but in this case the mortar joints were recessed and of good sound quality. Please contact Dyebrick for advice on matters of this nature.