Acid Staining--With acid staining, the pigment is mixed with an acid and applied liberally to the floor. Generally it is left overnight and scrubbed off the next morning and sealed. The effect can range from dramatic to hardly noticeable depending on the concentration of the product and the density of the concrete. One thing you can be sure of, the outcome will not be predictable to any large degree. In other words, the product 'does what it does' and will affect different areas of the floor differently given a modeled appearance.
Spray- On Dyes--Applying a spray-on dye allows you to apply the the product in several coats effectively controlling the amount of pigment or color you want on the floor. The dye can be applied immediately after cleaning and dries in about 30 minutes so that the customer can choose whether or not to have have additional coats applied. In this sense, the outcome is predictable and decisions can be made in real time whether or not to add more color or to even add a different color if desired.