We ordered this product to etch the glass (solid) on our new front door. The glass in the door measures 5'6"X2'3" - a large piece. One 22oz bottle is one application on one side which works well - etching on the inside, smooth glass on the outside. We used two bottles, although one would probably do it if you don't pour the product onto the glass first, then brush it, instead, pour the product into plastic containers and brush on in even strokes. We let it sit on the door for about 20 minutes, stood it up, then hosed it off. You will see some of the brush strokes but it looks intentional. If you pour it out, you will see where the product first hits the glass (we were left with an S pattern). We were able to get rid of almost all of this pattern with our second application. The product did not harm the door frame at all, not need to tape off (fiberglass/plastic). Great way to use this product!
