I have purchased several different sealers and tested them on my stacked stone. Most of them were like varnish, smelled like poison, and left a shiny "thick" imprint that looked awful to me. But this stuff behaves like water, enhances the stone, is odorless, washes with soap and water, and most importantly, you never realize you're using a sealant. When water hits it, it doesn't bead like varnish, but you know how it works because the stone doesn't change color, it stays enhanced. Apply an even coat to the entire exposed stone but not to the surrounding pieces of engineered stone. I've tried different techniques, thick-haired rollers, lots of brushes, but in the end I settled on this: I used a cheap hand-held pump sprayer and a sponge brush. Simply pour half a liter of Glaze-n-Seal into a spray bottle, pump to build pressure, then spray a small area. Use a sponge brush to redistribute the material as needed. The atomizer produces a fine but precise mist that can be controlled so as not to overspray the surroundings. Trust me, this procedure will save you hours. I applied 2 coats; The first layer takes a little more material as it penetrates the stone. I expect this treatment to last about 2-3 years in my area of Southern California where the weather is mild.