Staining colors concrete in a way that can't be achieved by any other coloring medium. Rather than produce a solid, opaque effect like paint, stains penetrates the concrete to infuse it with translucent tones that vary depending on the surface they are applied to. The results can mimic everything from polished marble to tanned leather to natural stone or even stained wood. Like stains for wood, concrete stains are semi-transparent and are intended to enhance rather than disguise the surface. They will not hide cracks, blemishes or other flaws in existing concrete. Nor will they completely mask an underlying color or conceal the texture of the surface. An existing concrete slab with major cracks or spalling is usually not a good candidate for staining because any patchwork is likely to show through the stain.