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Contents

• Coloring Render
• Coloring Plaster
• Concrete and Colored Screeds

Coloring Render

Obtain the desired render color you want by adding Ocher to mortar, stuccos and grout at a maximum of 10% Ocher to the weight of the base, either cement or lime. This preparation is then mixed in with sand.

Coloring Plaster

To obtain a colored plaster, either gypsum or lime based, incorporate between 10% and 18% Ocher or pigment to plaster by weight. For lime plasters, this calculation would be in relation to the lime powder before the addition of any aggregate. Saturation limits will be reached as Ocher or pigment levels approach 20%.
As an example:
10 lbs plaster mix w/ Dark Yellow Ocher @ 15% = 1.5 lbs Ocher (672 grams)

Ochers and pigments can be mixed with the dry powder in test quantities less than 5 lbs, but for ease of mixing large quantities, first slake (soak) the pigment in an equal or greater volume of water. Mix into a homogenous paste so that all the pigment particles are wet. This slurry can then be added to the wet plaster mix. The use of a mixing paddle attachment is recommended. When adding pigment color to plaster, it should be considered as an aggregate. Therefore it may be necessary to adjust the water to your mix, particularly when using Ochers. Rather than adding additional water, it may be sufficient just to thoroughly saturate the substrate before application of the plaster, and if necessary, light misting of the plaster with water while it is being worked.

For more information about the benefits of colored plaster refer to our page for Plasterers and Masons. For Lime Plasters please refer our Lime Coatings section.

Concrete and Colored Screeds

Ochre can be added at maximum rate of 10% of the weight of the cement before the addition of aggregate. The most attractive colors are obtained with light aggregates (sand and gravel) using white cement. For large quantities, add pigment directly to the cement mixer. Suitability tests must be performed.