We were very pleased with how our finished project has turned out. One of our biggest goals was to change the appearance of our brick. With a referral from a relative who used your product in the past we thought we would try it out for ourselves. We used 4 x Charcoal Kits at the initial dilution level (strongest). When we finished it turned out far better than our expectations. We have already recommended your product to people who have stopped and inquired about how we changed our brick. We have no doubt it will last for years to come. Thank You.