Thursday, February 01, 2018

Pigments and Paints

This post was written with help from Kabocha!  It also required a great deal of research, so I highly recommend you browse the Outside Resources section, especially if you find this topic interesting.


When it comes to watercolor, you have two options for generating color- pigments and dyes.  Everything else is just binder- gum arabic, aquazol, or even glycerin, or filler- optical brighteners like calcium or talc.  Although you can't paint with just pigment and water, pigments and dyes add color to our world in a variety of ways- from dying fabric to glossy paint coats in the automotive industry.

Humans have used pigments since cave paintings- usually accessible earth pigments collected straight from the ground, and dyes came shortly after.  While understanding dyes and pigments isn't mandatory for you to enjoy watercolor, understanding your materials can help you plan a course of action and allow you to make the most with the materials you have.

Every paint is a mixture of microscopic pigment particles, which provide the paint color, mixed in a liquid paint vehicle that holds the pigment in suspension, allows it to be applied with a brush, then dries to bind it to the support (paper, board or canvas). The vehicle also contains other substances that reduce manufacturing costs, adjust the visual appearance and handling attributes of the paint, and increase its shelf life in the art store.
Source: https://www.handprint.com/HP/WCL/pigmt1.html

How Paint Is Made- M Graham & Co


How Sennelier l'Aquarelle Water Colours Are Made


Dyes Vs Pigments

The difference has nothing to do with whether or not the product is derived organically.

A distinction is usually made between a pigment, which is insoluble in its vehicle (resulting in a suspension), and a dye, which either is itself a liquid or is soluble in its vehicle (resulting in a solution). A colorant can act as either a pigment or a dye depending on the vehicle involved. In some cases, a pigment can be manufactured from a dye by precipitating a soluble dye with a metallic salt. The resulting pigment is called a lake pigment. The term biological pigment is used for all colored substances independent of their solubility.[1]

Basically, pigments coat the object, like a coat of paint on a car (and may stain, may not, depending on the pigment), whereas dyes penetrate the object and stain, like dying fabric.

Pigment. Pigments are chemical compounds with appealing or useful color attributes and that do not dissolve in water....In contrast, a dye is completely soluble (dissolves) in water, and binds directly with the materials it contacts (though a mediating chemical called a mordant must often be present to make this bond happen).
Source: https://www.handprint.com/HP/WCL/pigmt1.html

For watercolor, GENERALLY higher quality watercolor are made from pigments, and student grade, washable watercolor is made from dye.  Dye based watercolors are not lightfast or waterfast, and while their water reactivity presents interesting options regarding techniques, you may find it frustrating if you try to use it like you would traditional watercolor.  However, dye based watercolors are vivid, clear, and bright, and neons are available which would not be easily available in pigment form.


Dye based watercolor created using Spectrum Aqua watercolor markers.

 Pigment based watercolor created using Winsor and Newton, Daniel Smith, and Holbein watercolors.


Pigments:

Single Layer watercolor painted with Holbein, Winsor and Newton, and SoHo watercolor
pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescencephosphorescence, and other forms of luminescence, in which a material emits light.
Source: https://en.wikipedia.org/wiki/Pigment

More simply:

pigment is something that is added to something else to give it color. Natural pigments can come from just about anything. Pigments can be made from animalsplantsrocks and minerals or even the ground itself, for example clay plus salts. Pigments can also be created by people.
Source: https://simple.wikipedia.org/wiki/Pigment


A pigment is simply a colored material that can be added to something else to give it color, but sits on top of the substance it has been adhered to as a coating. A pigment can be used to produce a dye.

Pigments fall into three categories:
Organic
Inorganic
Special

Organic Pigments

Mineral- Obtained from minerals and stones.  Inorganic.  Clay earth pigments, mineral and semi-precious/precious stone pigments, and metal based pigments fall into this category.  Many of these pigments are highly toxic, such as those derived from Cadmium (cad. red, cad, yellow, ect) or lead (Naples Yellow, lead white)

Examples:
Yellow Ochre (earth)
Lapis Lazuli (Ultramarine) (traditionally made from precious Lapis Lazuli)
Lamp black (carbon pigment)

Daniel Smith's Primatek watercolor line is made entirely from minerals specifically selected for beautiful, luminous color.

Science & Art Unite! Daniel Smith Watercolors



Most of these pigments are extremely lightfast.

Biological- Obtained from plants and animals or their byproducts.
Examples:
Tyrian Purple (derived from a mollusc)
Gamboge
Indigo (derived from the wode or indigo plant)


Synthetic Pigments 

Obtained by mixing components to make a pigment.  Although synthetic pigments have been available in some form for a long time, there was a huge boom in synthetic pigment discovery and production during the Industrial Revolution.

Examples:
Prussian Blue
Ultramarine (post Industrial Revolution)
Quinacridone colors


No other colors have both the intensity and transparency of the quinacridone family. They are synthetic organic pigments, created in the world's most advanced color laboratories. Minuscule pigment particles are exceptionally uniform in size and shape, which translates to unfailing behavior in the paint.

Source: http://www.danielsmith.com/Item--i-E-QUINACRIDONEWC


Synthetic pigments are often used to replace originals that are difficult, dangerous, or inhumane to obtain or use.  Examples include Indian Yellow (inhumane), Vermillion (toxic), and Ultramarine (rare).

Interested in a specific pigment, and want to learn more about how it's made?  Check this page out!  Or learn the history behind an entire color family by clicking here.

For more information on Organic Pigments, Inorganic Pigments, and Synthetic Pigments, and how they can affect your watercolor, check out this wonderful post by Jan Hart for the Daniel Smith blog.

Pigment Properties:

Staining:

Granulating:

In general, mineral, metal, and earth based pigments tend to be granulating, whereas synthetic pigments tend to be staining.  This is due to particle size- inorganic pigments tend to have larger particles, synthetics tend to have smaller particles.

Different pigments may have differing individual properties, so experimentation is a great way to get to know your palette!

I want to make my own!

Making Watercolor Paint- Owings Art


Making Your Own Watercolor Paints- P1- Eve Bolt-Bolt's Vault


Making More Watercolor Paints-P2- Eve Bolt-Bolt's Vault


DIY Watercolors-Mosspup


Making Charcoal Paint:


Vivianite Pigment- The Blue Ocher


Making Paints- Equipment&Safety: 


So what about Hues?

Hues are replacement colors for pigments that are no longer available, are prohibitively expensive, or are toxic.  An example would be cadmium based paints- these are frequently replaced with hues, as cadmium is quite toxic.

Dyes

Painted with dye based fountain pen ink
dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and may require a mordant to improve the fastness of the dye on the fiber.[1]
Source: https://en.wikipedia.org/wiki/Dye

In Layman's terms: 


Dyes are usually soluble in water whereas pigments are insoluble. Some dyes can be rendered insoluble with the addition of salt to produce a lake pigment.


Source: https://en.wikipedia.org/wiki/Dye


Dye is a substance used to color materials. It is often used to color the fabric used to make clothing. It has low solubility. A pigment won't do this because it won't stick to the fibers of the fabric and color them. A dye can be natural, usually made from plant material such as berries, or artificial, meaning that it is made by humans from chemicals such as petrochemicals.
Source: https://simple.wikipedia.org/wiki/Dye

A dye has low solubility, meaning it will reactivate and mix with an appropriate solvent (this can be something as simple as just water, or as specific as alcohol or other substances). Dyes are usually used for coloring substances, as they stain and bind to fibers and hair.

Dyes are common in inexpensive watercolor products, watercolor markers (excluding the Winsor and Newton Watercolor markers, which are pigments based), waterbased markers, liquid watercolors such as Radiant (excluding Hydrus, which is pigment based), and alcohol markers.  They are prone to reactivation when water is reapplied, which is why alcohol markers will blend.

This tendency towards reactivation are why dyes are the preferred choice of colorant in children's grade watercolors. Brands such as Crayola, Cra-Z-Art, and other children's watercolor manufacturors use dyes for washability.


Types of Dyes:
Acid Dyes- Typically used to dye fabrics such as silk, wool, and other protein fibers.  Brilliant and colorfast.  Acid dyes are known to produce the most vibrant colors.
Basic Dyes- Cationic stains that react with material that has been negatively charged.  Available in synthetic form, these are aniline dyes that act as bases.  Color base is not water soluble, so base is converted into a salt first.  Useful for tinting and brightness.
Direct/Substantive Dying-Adheres to the object being dyed by non-ionic forces.  Work best on texiles with high cellulose content, such as cotton.
Mordant Dyes (see Lake Pigments below)- A mordant is a dye fixative, that sets dyes on fabrics.  A mordant dye is the same as a lake pigment, and is more color fast than unfixed dyes.
Vat Dyes-Vat dyes are applied in a vat or bucket, and this applies to almost any dye, including acid dyes, direct dyes, and fiber-reactive dyes.
Reactive Dyes-primarily used for tinting textiles, these are a class of highly colored organic substances.  These dyes attach to the substrate by a covalent bond, and the dyestuff becomes part of the material.  This increases colorfastness.
Disperse Dyes- Synthetic dyes.  These dyes are a one of a kind organic substance free of ioning groups.  These dyes are less soluble in water and are used to dye synthetic materials.  Disperse dyes are non soluble, so a dispersing agent is necessary for dying.
Azoic Dyes- produced by a reaction between the coupling compound (napthol) and a diazo base or salt.
Sulfur Dyes-Cheap, have good wash fastness, easy to apply.  Predominantly brown, black, or dark blue, with reds being unknown, but pink and lighter scarlet dyes available.  Most commonly used dyes manufactured for cotton dying.  Water-insoluble and require a reducing agent to disintergrate.

Organic Dyes

The majority of natural dyes are plant derived.

The Chemistry of Natural Dyes- Bytesize Science


Plants Used for Dye:
Woad- Indigo
Weld- Neon Yellow
Madder-Reds
Brazilwood- Rich reds
Logwood-purples, greys, blacks
Old Fustic-strong dark yellows to peach
Safflower- Reds
Red Cabbage- wide range of color

Mineral Dyes:


Synthetic Dyes:


Man-made dyes, usually stemming from the petrochemical industry, using mineral derived components.  


An example of a synthetic dye would be aniline dyes.

Aniline dyes: Aniline is an organic compound mainly used in industrial chemicals.  In 1856, the first aniline dye, mauvine was discovered, which lead to the production of other synthetic dyes. 

Examples of Aniline Dyes: 

mauveine
fushsine
safranine
induline

I want to Make My Own!

Hibiscus Dye, Pigment, & Paint Fail:



DIY Natural Watercolour Paints- Our Raw Beauty: 


Onion Skins Natural Dye Tutorial


Natural Dyeing Process- Design Studio 1


Natural Indigo Dyeing and Shibori- Meghan Greenholt


DIY Dyes from your Kitchen and Garden: Magic of Living Color


Hibiscus Dye, Pigment, & Paint Fail: 




Making an Azo Dye (and coloring some socks!) | Dyes & Pigments




Examples of dye based watercolor:
Dr PH Martin's Radiant Concentrated Watercolor
Ecoline Watercolor Markers and Liquid watercolors
Blick Liquid Watercolors
Sargent Liquid watercolors
Spectrum Aqua Watercolor markers
Crayola Washable Watercolors
Peerless Watercolors
Brusho

Dyes You Can Make at Home:
Onion skins
Tea
Coffee
Tumeric
Beets
Walnut Husks
Red Cabbage

Read more about the process here.

Color Chromatography
Happens in dyes, not pigments

Play with it at home:
Color Chromatography


Lake Pigments


lake pigment is a pigment manufactured by precipitating a dye with an inert binder, or "mordant", usually a metallic salt. Unlike vermilionultramarine, and other pigments made from ground minerals, lake pigments are organic
Source: https://en.wikipedia.org/wiki/Lake_pigment

Lake pigments are manufactured by making a dye into a form that can be turned into a powder or similar substance.  Lake pigments are usually made out of organic materials, rather than mineral-based.

Typically not lightfast, given their dye origins

What are Lake Pigments- Nada Makes:



The Chemistry of Natural Dyes- Bytesize Science:



Making a Dye, Lake Pigment, and Paint from Red Cabbage



Organic Lakes to Pigments- Michel Garcia and Yoshiko Wada:


Examples: 
Carmine (cochineal) 
Indigo
Rose Madder

So can you make faux pigments by mixing dye+chalk, and is this what most cheap watercolor brands do?

Yes, but adding chalk adds problems.  Adding chalk dilutes the color in most cases, and can alter the color completely for some dyes.

Process for making most paints from a dye or natural dying substance seems to be: 

  • (When using biological matter, boil or crush to release juices/sap, boil)
  • Concentrate
  • Allow to add mordant (frequently alum and a little washing powder)
  • Strain
  • Add remaining sediment to a coffee grinder, grind
  • Use a muller to grate to a micro powder, probably add gum arabic or honey, or glycerin?


Making Acrylic and Oil Paint from Gentian Violet (Crystal Violet)



Outside Resources:
Color of Art Pigment Database
Making a Paint and Pigment out of Cholorphyll
Making Acrylic and Oil Paint from Gentian Violet (Crystal Violet)
How to Make Paint Pigments for Art Projects

Winsor and Newton: Masterclass- Pigment Analysis
Using Herbs as Dye- 18th Century Garden Technique
Wet Canvas- PrimaTek Colors
Daniel Smith Primatek Watercolors- Sandy Allnock
Buy Paints Made with Natural Dyes
Peerless Watercolors
Making Paint out of Colored Chalk- Nada Makes
Alternative Oil Paint Muller-Easy, Cheap, D.I.Y Oil Paint Muller- Nada Makes
Adding Honey and Glycerin to Watercolor Paints
Jan Hart: Why Paints Work The Way They Do, Explaining Organic and Inorganic Pigments
Daniel Smith: Quinacridones Colors
Wikipedia: Society of Dyers and Colourists
Definitions of a Dye and a Pigment
Wikipedia: Lake Pigment
Wikipedia: Pigment
Wikipedia: Dye
Simple Wikipedia: Pigment
Simple Wikipedia: Dye
Primatek Watercolor
Science and Art Unite with Daniel Smith Watercolors
Jacquard Products: Acid Dye
Food Color World: Basic Dyes
Wikipedia: Substantive Dye
Wikipedia: Mordant
Wikipedia: Vat Dye
Dyecolours: Reactive Dyes
Textile Fashion Study: Disperse Dyes
Dyeing with Azoic Dyes
Dying Fiber to Apparel
Wikipedia: Azo Dye
Wikipedia: Sulfer Dye
Mordant Dyes
Wildcolors: Natural Dye Mordants
Wildcolours: Top 3 Dyes
Wildcolors: Tropical Dyes
Wildcolors: Safflower
Painting with Natural Dyes
Pigments
Pigments Colors
Handprint: Pigment
Wet Canvas: Daniel Smith Prima Tek Colors
Pigments Complete Earth and Ocher Set- Unboxing Review and Comparison
Introduction to Earth Pigments
Making Ochre Paints Tip 19
A Story of Blue- Nature Video