It is interesting to look back through the history of impregnators/penetrating sealers and their importance in the marketplace. In the early days of tile and stone installation, sealing tile, grout or natural stone was not an accepted practice. Sealing was looked upon as a nuisance more than an aid. Every possible excuse you can think of was used: "I don't want the liability of sealing," "I have had problems using sealers in the past," "I have to charge extra to use a sealer," "I don't want to come back for the extra day it takes to seal," etc.