Article: Before you start your etching, you'll want to make sure you have enough of a suitable acid to complete your project — having to run out to the hardware store in the middle of your etching project is a serious pain. Muriatic acid (also called hydrochloric acid) is the most common type of acid used for this project. It's difficult to say exactly how much acid any given project will need because the acid is usually sold in varying strengths. In very general terms, 1⁄4 gallon (0.9 L) of acid (when properly diluted) will cover about 50-70 square feet of concrete (about 4.5-6.5 square meters).  Other suitable acids for etching include phosphoric acid and sulfamic acid. The latter is an especially good choice for first-timers because it is much less caustic and dangerous than the other acids.  If you're unsure of whether you have the right type of acid, check the label on its packaging — most suitable products will mention that they can be used for concrete etching purposes. To begin, remove any any all furniture, vehicles, and other obstructions from the area you intend to treat. Etching acids can permanently damage common objects if allowed to remain in contact with them for even short periods of time, so have them well out of the way by the time you start your project. You'll also want to give the area a good sweeping to remove accumulated dust, dirt, or grime. The acid needs to be able to touch every part of the concrete's surface to react properly with it. Even small pieces of debris can interfere with the reaction, potentially causing an uneven etching. If you're etching concrete in your garage or on your driveway, there's a chance that there may be oil or grease stains on the driveway from your vehicle. Etching acids can't penetrate through oily substances, which means that any concrete under an oil stain will go un-etched. To remove oil and grease stains, try scrubbing with a commercial degreasing product — these are available from most home improvement stores for fairly cheap. Alternatively, try using ordinary laundry detergent. Most detergents are formulated to dissolve oil and grease, making them perfect for degreasing your concrete surface. When your concrete is perfectly clean and clear, use a hose with a sprayer attachment to wet the entire surface of the concrete. Spread the water evenly across the surface until all of the concrete is wet but no standing water remains. The concrete should stay at this level of wetness until the acid is applied. If you'll be etching up to any adjacent walls or other surfaces, be sure to also wet the bottom inch or so to minimize the possibility of direct contact with  the acid.

What is a summary?
Grab muriatic acid or another suitable etching acid. Clear the concrete of any obstructions. Use degreaser for oil or grease. Hose down the entire area.