Rather than reiterate what others have already done very well, I will mostly just put my own experiences and experiments here. I have also assembled some links to some great and informative paint making sites that have far more detail instructions on grinding and mulling your own paints than I have time to create.

For Pigment Information Sorted by Color Index Name Click Here

Some links to paint making information: ^Top

Natural Pigments has a Step by Step guide to grinding water color paints. they also have hard to find historical and earth pigments for sale, as well as additives and paint making tools.

Paintingmaking.com an excellent site covering all aspects of making paint

Sinopia has a small step by step page as well as hundreds of modern pigments, historical pigments, and additives for sale

The Society of Tempera Painters has useful information and a step by step example.

Paint Making And Color Grinding by Charles L. Uebele. pub.1913 now in the public domain.

Experiments : ^Top

Water soluble oils:

The current water soluble oil paints are not quite up to the standards of a real artists paint, so I tried mulling my own. i used both Dou water mixable linseed oil and Lukas water soluble linseed oil to grind the paints. I added a small amount of Dorlands wax medium as a stabilizer, which didn't seem to effect the water solubility at all. The results were indistinguishable from regular artist grade paints and actually better than most.

 

Pigment Manufacturing Recipes and Info:   ^Top

Earth pigments and "Found" pigments:

Many things have the potential to be made into pigments. Most localities have colored earths, minerals and clays that are virtually the same as store bought earth pigments. They simply need to be pulverized, levigated and washed. There are also many unique colors and minerals in many locations.
Dyes, plant juices and other colored liquids may be able to be precipitated on to Aluminum Hydrate to form lakes. Although most dyes and plant colors are fugitive, some may be found that have acceptable light fastness. Only actual experiments can tell if a new substance will be acceptable as a pigment.
Other things can be made into pigments as well. Possible candidates for pigment experimentation could be pulverized bricks, colored glass, pottery, rust scrapings, other "found" substances, etc. I would propose that the qualities for making a good pigment are as follows:

1.) it can be pulverized or ground fine enough to make an acceptable pigment. This can be a matter of personal preference or a desired effect.
2.) it must be stable in it's natural state and not likely to react to environmental conditions or with other pigments.
3.} it should not have an adverse effect on the binder, either chemically or physically
4.) It should be insoluble in all potential binders.
5.) It should be free of organic matter that may decompose or rot.

Other than the above criteria I would say anything goes. Light fastness and other working quality's can only be attained after the paint has been made in the binder of choice and tested, then the pigment can be accepted or rejected according to ones own criteria.

Making Natural Earths and other found substances into pigments:

The first step to making a pigment would be to pulverize and powder the substance. You may need to start with a hammer to brake it up and then grind it down finer with a mortar and pestle. Forcing it through a variety of sieves or screens may help separate finer particles for further grinding.

The pigment can then be washed by mixing with water and allowing the pigment to settle for an hour or so. Carefully pour off the water and repeat until the water is clear.

The next step is to levigate the pigment. This is similar to the previous step of washing except you'll only leave the pigment settle for a few minutes.
Mix the pigment with water as when washing, but this time only allow it to rest a minute or two so that the heavy sand and larger grains settle to the bottom, but the finer particles are still in suspension. Carefully drain off the water into another container so as to get as little as possible of the sandy bottom particles. Now allow the water to settle a day or so until the water clears. Drain off the water and allow the rest to dry. A Buchner funnel will quicken the process up considerably. Then re-grind the pigment in a mortar and pestle and screen through a very fine screen such as a permanent coffee filter.

If the resulting pigment is still to course for your needs, it can be re-ground and levigated as many times as needed.

Michael Price is some more information on levigation techniques & equipment here. (off site)

 

Chrome Yellow

Glassware needed: 1) 100 mL beaker, 2) small (10 mL) graduated cylinder, 3) buchner funnel, 4) filter flask

Measure 5mL potassium chromate solution using the graduated cylinder and transfer (pour) the solution to the beaker. Rinse the cylinder well with distilled water, then measure 5 mL of zinc chloride solution. Add the zinc chloride to the beaker. Stir with a glass rod. Using a disposable pipette, add 10 drops of sodium hydroxide. Note carefully all changes you observe. Isolate the chrome yellow pigment using a Buchner funnel, filter paper and filter flask. Rinse the pigment with water and allow to dry on the filter paper.

 

Prussian Blue

Glassware needed:1) 2 small beakers, 2) glass funnel

Weigh 0.410 g of iron(III) chloride [Fe(III)Cl3]in a weighing boat. Weigh 0.470 g of potassium ferrocyanide [K4Fe(CN)6] in another weight boat. Carefully add one or two pipettes of water to dissolve each solid separately in the weigh boat, then also carefully pour each solution into a beaker. if not all the solid has dissolved, stir with a glass rod. Now, add the solution of Fe(III)Cl3 drop wise (using a pipette) to the K4Fe(CN)6 solution. Stir briefly the allow the mixture to sit about 10 minutes.

Drying method 1:
Place the glass funnel into a ring-clamp on a ring stand. Place a beaker 9 any size) under the funnel. Flute filter paper and place it in the funnel. Finally pour and scrape the Prussian blue pigment formed into a fluted filter paper in a glass funnel. Allow the thick mixture to slowly drain the excess solution away down the funnel. Leave the pigment on the filter paper ad place it on several paper towels (labeled) to dry over the next week.

Drying method 2 (preferred; this method can be used for drying most pigment precipitates):
First separate the coloured solid from the water by filtration. Set up a Buchner funnel, filter paper and Buchner flask as shown in the diagram. Connect the Buchner flask to the water pump and turn on the water supply. Carefully pour your liquid into the Buchner funnel. The water will be sucked away leaving your coloured solid behind.

The next job is to remove any remaining water from your solid. Carefully scrape your solid into a small beaker using a spatula. Measure about 10cm³of propanone (acetone) in a measuring cylinder. Take great care not to spill propanone (acetone) on your skin or get it in yours eyes. Don't sniff it, either. Pour the propanone (acetone) into the beaker and stir the mixture with a stirring rod. Put a new piece of filter paper in the Buchner funnel. Filter the mixture as you did before.

Finally, you are ready to make the dried solid into an artists' paint. Transfer the solid to a mortar. Grind it carefully with a pestle. Your pigment is now ready to be stored or ground into paint.

Notes: water is miscible in acetone (propanone) and it will draw the last bits of water from the pigment. It will also remove many the impurities.

Another recipe for Prussian Blue:
Make Solution 1 by dissolving 2g of iron(II) sulphate in 4cm³ of distilled water. Make Solution 2 by dissolving 1g of potassium hexacyanoferrate(III) in 3cm³ of distilled water.
Make your blue colour by adding Solution 2 to Solution 1 drop-by-drop, swirling the flask thoroughly each time. The blue precipitate should be washed and filtered and set out to dry.

 

Verdigris

Obtain a small and large set of petri dishes. Place the top of the small petri dish inside the bottom of the large petri dish (see example in lab). Using a disposable pipette, place about one pipette (~ 1 mL) of glacial acetic acid into the bottom of the large petri dish, carefully avoiding dropping any acid into the small petri dish. Using the metal snips, cut a piece of copper sheet that is about 30 x 50 mm (1" x 1.5"). Clean the copper using the metal polish provided. Wipe the residue carefully and polish until the metal is a rosy copper color. Carefully place the piece of copper metal on the small petri dish. Place the large top cover on the petri dish and wrap a piece of parafilm around the side.

  Notes:The basic principle here is to expose the copper to the acetic acid fumes in a closed container, without allowing the copper to be in direct contact with the acid. Any number of apparatus that accomplishes that goal should work. Small glass jars or cups and a mason jar would be an easy substitute for the petri dishes in the recipe above.

 

Verdigris (harvesting)

Remove your verdigris-coated copper plate or pipe from the petri dish or jar and place it on the inverted petri dish top. Allow the verdigris to "dry"; it will become paler and powdery in appearance. Scrape the verdigris off onto a piece of glassine (or weighing) paper. Store the verdigris in a vial and label it.

 

Viridian

Glassware needed: 1) mortar and pestle, 2) small crucible, 3) triangular wire support . 4) 150 mL beaker, 5) buchner funnel, 6) filter flask

Obtain a mortar and pestle. Place into the mortar 3 g of sodium dichromate and 0.45 g of sulfur. (Weigh out the needed amount of each solid on a plastic "weighing boat".) Grind the two solids together until they are a fine powder. Transfer this powder to a small porcelain crucible using "glassine" or weighing paper. Set the crucible on a triangular wire support. Heat the crucible in a flame from a bunsen burner until no further gas or smoke is produced. Allow the crucible to cool. When you can safely handle the crucible with your hands, scrape out the solid product and put it back into a **CLEAN** mortar and pestle. Grind it again then transfer it to a medium sized beaker (150 mL) being sure to remove all the powder by washing (rinsing) the mortar with water. Fill the beaker with water approximately halfway and stir vigorously. This process is dissolving ( "extracting") into the water any undissolved reagents (what, if any, color(s) do you observe?). The green chromium pigment will be left undissolved in the beaker. A Buchner funnel, filter paper and filter flask are used to isolate the pigment. Rinse the pigment with acetone to help remove water and speed drying.