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Pigment Selection for Cosmetics

The art of color cosmetics is exciting and constantly evolving value-added benefits for consumers in today's market. Whether they are pale and minimalist, earthy or ethereal, or packing a vibrant punch, color comes in all facets and hues.

Become an expert by learning the complete knowledge on pigments used in various cosmetic applications. Find out here:

 » The Basics of Color Cosmetics
 » Types of Pigments Used in Cosmetics
 » Selecting the Right Pigment for Specific Application

Colorants Used in Cosmetics Formulations


TAGS:  Pigments    

Pigments for CosmeticsColorants appear certain colors based on the wavelength of light they reflect. Color can be measured and described using spectrophotometers. But, the trained human eye can achieve good color matches just as effectively.

Terms used to describe color include:  


  • Hue – This is the actual color, e.g. red, blue or yellow
  • Value or Luminosity – The higher the value or luminosity, the more white that is in the color
  • Chroma or saturation – The intensity of the hue relative to the value or luminosity of the color

Colors are measured using a variety of systems, which can include:

  • Pantone color charts
  • The Munsell color system
  • The British Colour Council Dictionary of Color Standards

Color selection charts

Opaque vs. Translucent vs. Transparent - Know The Difference!


Colors may also be perceived as:

  • Opaque - Solid color, which cannot be seen through. This is an important property of color cosmetics where coverage is required e.g. foundations, concealers, lipsticks.

  • Translucent - Objects appear cloudy with a color; they cannot be seen through completely. This is an important property of color cosmetics where subtle color is required. Here, the users skin tone is desired to be enhanced but not completely covered e.g. translucent ‘finishing’ powders, tinted moisturizers, tinted lip glosses.

  • Transparent - Objects can be seen through, and appear optically clear although colored. This is more for aesthetic effects of the product. Also, where the intensity is quite weak, will wash off with no lasting color on the user’s skin e.g. a variety of every day personal care cleansers and lotions with colored accents. Bronzers used in self-tanning products also fit into this category although their use is in much higher concentrations to leave a lasting stain on the user’s skin.


Types of Pigments


Organic Pigments


Classified as ‘organic’ because they contain carbon (and are often based on benzene ring structures), organic colorants include lakes, toners and true pigments.

  • Organic colorants are all transparent on the skin, with various levels of chemical and physical stability. They are capable of producing a range of bright colors for a variety of visual effects.

  • They achieve best stability in the pH range of 4 to 9 and are often unstable in the presence of metal ions. Chelating agents can be a good addition to formulas where metal ions might be otherwise present, so long as the chelating agent does not have a detrimental effect on other components of the formulation (such as some fake tanning agents).

  • Organic colorants can also be classified chemically by their structures with varying stability, such as:

    • Azo colorants
    • Xanthenes
    • Triarylmethanes
    • Quinoline
    • And indigoid

    Organic Pigments
    Examples
    Lakes

    Toners


    True Pigments
    (Most Stable Form)


  • Certain organic colorants can also be used to stain the skin or the lips, for various effects. So called ‘bronzers’ used in fake tanning products usually use a combination of dyes that are able to stain the skin and are resistant to easy wash off.

    While some colorants would normally be used only in wash off products, in bronzers, the ‘stain’ effect is desirable to give an instant ‘tanned’ appearance. Examples of colorants used to obtain a tanned stain in the skin include:
    Other skin staining dyes that may be used include those that are oil soluble and stain the lips. These typically include:
    All skin staining colorants are prone to risks of causing allergic reactions. Particularly the oil based colorants used in lipsticks. Appropriate consumer safety tests should be conducted to confirm safety before products move beyond the sample and development stage


Inorganic Pigments


Consist of iron oxides, chromium dioxides, ultramarines, manganese violet, white pigments and pearlescent effects.

  • They are used for their opaque color coverage, making their use particularly suitable in face and eye make ups.

  • They are usually duller in appearance than organic pigments. However, they have much better stability and can be enhanced through various coatings for decorative effects (pearlescent colors).

  • They are stable to heat and light but may be sensitive to extremes of pH.
    Inorganic Pigments in Cosmetics


  1. Iron oxides: It has three basic shades - yellow (CI 77492), red (CI 77491) and black (CI 77499). Through careful blending, these three colors are able to produce a vast array of:

    • Tans
    • Umbers
    • Browns
    • And siennas

    Making them ideal for use in foundations, blushes and lip products.

  2. Chromium oxides: It has two basic types:

    • One provides a dull yellow/green hue
    • And the other a bright bluish/green hue.

  3. Ultramarines: They can vary significantly in color, from blues and violets through to pinks and greens.

    • No matter the color, they all have the same CI number and INCI designation.
    • Also, they are unstable to low pH conditions.

  4. Titanium dioxide: It is widely used in color cosmetics where opacity and coverage is required.

    • It is extremely stable to heat and light
    • And easily incorporated into a variety of colored cosmetic and personal care products.

  5. Zinc oxide: It has a lower intensity of ‘whiteness’ than titanium dioxide and less coverage.

    • It does impart antibacterial and fungicidal properties
    • And has good heat and light stability.


 » Also Find Some Amazing Natural Colorants Options for Your Cosmetic Formulation! 


Selecting the Right Pigment


While working with colorants/pigments, one need to obtain and understand ‘color charts’ from suppliers in order to determine the colorants you want to use. As shown in color charts below, one could typically see a color bar between two colors provided. One is light and the other has a darker shade. These are referred to as reduced shade/full shade, and show:

  • Reduced shade - This is the lighter of the two colors, and gives a visual reference for how the color will look when it is ‘diluted’. That is, when added to base product at less than 100% strength.

  • Full shade - This is the darker of the two colors, and gives you a visual reference for how the colorant looks at 100% strength.

Figure below shows an example of color chart:

color chart 
 reduced full shade
Figure : Color Charts

Here, reference to particle size in charts could be seen. Typically, particle size will yield the following effects:

  • 1-15µm provides velvety, soft and matte shimmer visual effects
  • 5-25µm provides a silky skin feel and smooth, silky and satin effects
  • 10-50µm provides strong color and some sparkle effect
  • 20-150µm provides a strong and pronounced sparkle effect
  • Larger particle size will provide an even stronger sparkle effect

 » Keep Updated with the Global Trends in Color Cosmetics! 


Creating Pearlescent Effects


Pearlescent pigments

Many pearlescent pigments are created by coating mica with titanium dioxide and iron oxides, to vary the refractive index observed in the finished product. Various thicknesses of titanium dioxide are used to vary the color effects that are created through the different refractive angles that are created. These refractive angles can also manipulate the visual effects of the finished products.

Additionally, iron oxides combined with the titanium dioxide coating can create a two-tone or luster effect. A variety of metallic and bright colors can be created using the pearlescent coating effect.

Figure below depicts how titanium oxide and iron oxide are used to create pearlescent effect:

Pearlescent effects 
Figure: Titanium and iron oxide coating around mica to produce pearlescent effects

Other substances may be used to create pearlescent effects. For a substance to have pearlescent effects, its particles must be plate-like with a high refractive index and allow specular reflection. When using pearlescent pigments, it is important not to mill the particles extensively otherwise the reflective properties can be damaged.

Additional pearlescent effects can be created through the use of:

  • Bismuth oxychloride

    • Produces a silvery-grey pearlescent effect
    • At 8µm, it creates a smooth, opaque luster
    • At 20 µm, it creates a brilliant sparkling look

  • Treated pigments

    • Pigments can be surface treated for enhanced aesthetic performance as well as for process improvements
    • Aesthetic improvements include : better skin adhesion, longer wear, smoother feel on the skin, appearance improvements and easier application
    • Process improvements include : easier dispersion, smoother pressings, reduced sebum absorption, more even blending and less moisture absorption
    • Surface treatments may include lauroyl lysine, ester coatings, lecithin, zinc or magnesium stearate, and even nylon or polyacrylates for enhanced skin feel

  • Light diffusing particles

    • There are mainly used for an instant ‘wrinkle filling’ effect
    • Examples include barium sulfate, silica, mica coated with silica spheres, titanium dioxide, barium sulfate, aluminum hydroxide and polyethylene; to name a few
    • There are several varieties and more coming out constantly to provide consumers with an instantly younger appearance
    • These substances do not fill the wrinkles so much as diffuse light while being transparent on the skin, to remove shadows that would normally fill wrinkles and give the appearance of depth

Creating pearlescent effects

Be Prepared for Multiple Samples!


As with all developments, you’ll need to prepare multiple samples before you achieve the desired result. Also, this is never truer than when working with color! Make sure you finalize your base product first and select your pigments to achieve the desired opacity and shimmer first before working on the color. Then it’s just a matter of time and multiple samples till you’ve mastered the art of color creation!


Commercially Available Pigments for Cosmetic Formulations






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1 Comments on "Pigment Selection for Cosmetics"
Kim Y Jan 20, 2017
This is a good article, esp. since it gives characteristics of pigments including stability & solubility. I wish there was a section on Natural (plant-based) colorants, like carmine, madder, indigo, woad, saffron, etc.

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