Stain Treatment

Stain Treatment

StonePly panels are made of natural stones, porous by nature, and can easily absorb stains. Learn how to remove any stain with ease by using a poultice here.

StonePly stone panels are made from natural marbles, granites, and limestones. All natural stones are porous by nature and easily absorb stains. However, removing stains can be made easy by using a poultice, a material to absorb the stain from the stone. It is important to identify the type of stain so that the proper type of poultice mixture is used.

What is a Poultice?

A poultice is an absorbent powder mixed with a chemical designed to remove a stain from the surface of stone. The poultice powder materials can be found at most hardware stores and include

  • white molding plaster
  • talc
  • white chalk
  • various clays

Sometimes, in lieu of a powder poultice, an absorbent material such as paper towels, gauze pads, or cotton balls can be used.

If using a powder poultice, the poultice should be mixed with the appropriate chemical to form a thick paste.
If using an absorbent material poultice other than powder, the material should be soaked in the chemical and then rung out so it is moist, but not dripping.

Stain Treatments

Biological Stains (fungus, mildew)

Most biological stains can be easily removed without the use of poultice by using a water/bleach, water/ammonia, or water/hydrogen peroxide combination.

  1. Dilute 1/2 cup of bleach, hydrogen peroxide, or ammonia into one gallon of water
  2. Clean stained area thoroughly
If the stain still remains, then a poultice can be made with a white powder and one of the diluted chemicals listed above.


Efflorescence is when naturally occurring mineral salts inside real stone are brought to the surface by evaporating water. It appears as a white, powdery substance on the surface of the stone. Normally this is a temporary problem, and the white powder can simply be wiped away from the surface. Once the stone dries out, efflorescence should not be a problem. 

Learn more about efflorescence and what effect, if any, it has on StonePly.

Ink Stains (pens, markers)

Pen and marker stains are extremely hard to remove from the surface of natural stone.

For dark stones, acetone can be used to clean the surface of the stone where the stain appears.
For light stones, a carefully applied mixture of water and bleach.

For a less direct approach, a poultice can be used by combining the white powder with the appropriate chemical from above.

Metal Stains (rust, copper, bronze)

Iron or rust stains are the most common metal stains found on stone, and possibly one of the hardest stains to remove. It may take several poultice mixtures to successfully remove a metal stain entirely.

For rust, a poultice mixed with white powder and any rust remover chemical should be applied to the stain.
For copper, a poultice mixed with white powder and diluted ammonia should be used.

In both cases it may take several tries before you notice any results.

Oil Stains (grease, cooking oil, tar, cosmetics)

Before trying a poultice mixture, try cleaning the surface with diluted ammonia or mineral spirits. If this does not remove the stain, you can try to clean the surface with acetone (for dark stones) or diluted bleach (for light stones). If both of these methods do not yield results, then a poultice made of white powder mixed with mineral spirits can be used.

Organic Stains (coffee, food, tobacco)

Organic stains can be removed by using a powder poultice mixed with either:

  • acetone for darker stones
  • diluted hydrogen peroxide for lighter stones

Applying the Poultice

  1. Spread the poultice over the stained area using a wooden or plastic spatula (the poultice should be 1/4" to 1/2" thick)
  2. The poultice should be covered and sealed with plastic for 24 to 48 hours or until the poultice is dry (to aid in the drying process, holes can be poked in the plastic)
  3. Once the poultice is dry, it should be removed with the wooden or plastic spatula, and then the area rinsed thoroughly
  4. For stubborn stains, repeat this process several times as necessary.

Additional Notes

  • Any "whitening" chemicals used such as bleach, ammonia, or hydrogen peroxide should be diluted with water
  • Re-polishing may be necessary on some stones