Making paints :: Paintings :: Grosse is a geek

Making your own paints
Sometimes, you need to get have a special paint.

If you buy a tube of paint, you actually don't know what is in it. There might well be the correct pigment in it but has it been adulterated with something and the other ingredients are covering it up? Maybe you need a paint with a pigment that for some reason costs what you consider to be too much money or maybe you can't get that paint at all. These are all reasons why you might want to make your own paint.

On this page, we'll cover:

Introduction;

Pigments;

Grinding pigments;

Water Colours; and,

Oil paints.

Introduction

First of all, what does a paint need to do? A paint is applied to a surface so that it can modify the way that the surface reflects light. In order to achieve that, we conventionally have a chemical compound of some sort that interacts with light effectively glued to the surface. The conventional name for the compound that reacts with light is a 'pigment' and the glue is called the 'medium' (because it holds the pigment to the layers underneath the paint - in effect, it is in the middle, hence the name).

Ideally, the paint should have a life span that is appropriate for the purpose therefore the pigment and the medium should both be stable against light and the chemical and physical environment that they find themselves in. Ideally, they shouldn't react chemically with each other and additionally, the different pigments in the painting shouldn't react with each other either, or if they do, they should be protected from each other by the medium or an additional layer that is painted between them like a protective 'varnish'. Just consider just how long paintings are kept for.

So, what makes a good pigment? Essentially, all pigments are largely transparent. Even titanium white is - if you put it into a liquid with the same refractive index (the amount by which it slows down light) then light will not be bend when it travels into a grain of titanium dioxide or again on the way out therefore it will not reflect off the interfaces between the pigment and the liquid. However, each pigment slows down light to a different extent and some chemicals even do it differently according to the orientation of the crystal lattice and the angle of polarisation of the light.

Basically, the greater difference between the refractive index of the pigment and that of the medium, the more opaque the pigment. If a pigment's refractive index is fairly close to that of the medium it will be fairly transparent.

What makes a good medium? The medium should:

be transparent;

be colourless;

be dimensionally stable - not shrink or expand with changing humidity or other environmental circumstances;

be able to wet the pigment;

not react with the pigments;

keep the pigment distributed evenly throughout it during storage;

stick to the surface you are painting and to previous layers of itself;

protect the pigment from the environment;

set solid but with a bit of remaining flexibility;

have a solvent that makes it mobile enough to paint with (or some other temporary way of making it mobile such as heat in encaustic painting).

With water colour paints, the medium is usually acacia gum (gum arabic) to which a little honey is added as a humectant - the honey allows better mixing with water and when the paint dries, being fructose, it sets solid.

With oils, linseed oil is the best as it has a high concentration of the oils that react with air to polymerise which forms a flexible plastic that holds the pigment well. There are other so-called 'drying oils' such as walnut oil, safflower oil and so on but they are not as strong.

Additionally, avoid oils that are washed with caustic soda or other alkalis because doing so starts off something called saponification which essentially breaks down the oil to make a soap which will make it more susceptible to reacting with some pigments. (You can make soap by heating an oil such as olive oil with a strong alkali such as caustic soda (NaOH) solution and it will break down the oil into the sodium salt of the long-chain fatty acid and glycerol - the former being what we call 'soap' but be careful if you want to have a go at this by making sure that all of the caustic soda has been removed as it can cause serious burns. Essentially, don't do it.)

What makes a good solvent?The solvent should:

be able to dissolve in the medium (or the pigment);

not chemically react with the pigment (or the medium);

make the viscosity of the resulting solution low enough to be easy to paint with;

only contain volatile compounds - if there is something else in there, you will be adding that to your paint and that is not a good thing. Some turpentines have non-volatile compounds in them and these will prolong drying times as they need to oxidise themselves. Ideally, you should be able to add turpentine and if you add too much, you can let it evaporate to the correct level. You can perform a basic test on a turpentine sample by putting a few drops onto a non-absorbent surface and letting the volatiles evaporate - what is left ends up in your paint but ideally, there should be nothing left. If you evaporate a few drops of double distilled English turpentine like this, there will be nothing left;

Either be harmless or smell. A solvent that isn't harmless that is not particularly smelly can do you damage without you knowing about it. For instance, if solvent fumes were at an elevated level and you could smell them, you would know that you should open a window or take similar action to reduce the solvent you were breathing in. However, if you couldn't smell it, you could be doing yourself harm without knowing about it until, potentially, damage could have been done.

So, ideally, you should be using just water for watercolours or using double distilled English turpentine for oils.

Back to top

Pigments

If you are going to go to the trouble of making your own paints then don't use pigments that don't fit your specifications.

This is vermilion which is the manmade/ purified version of the natural rock cinnabar. As you can see, it is already nice and fine and if you want to make a paint from it, it is already fine enough so really, it is just a case of mixing it with the medium.

However, if it is cinnabar you want, sometimes this is passed off as cinnabar. It is the same chemical - Mercury Sulphide (HgS). Vermilion, having never come from a larger crystal in its current solid form, is as fine as it is going to get and so has an almost orangey hue about it and if you grind cinnabar until the particle size is the same, you will get the same results.

Vermilion comes from a chemical purification process and so is very finely divided.

There is no non-zero safe level of mercury so whilst this comes as granules rather than powder, it is still best to handle it wet. Mercury is a neurotoxin.

Cinnabar however, is the rock from which it comes and so as to demonstrate that what you are buying is the real thing, it is supplied in a granulated form.

The picture on the right and the one of vermilion above it are at the same magnification so you can see how they differ (field of view is around 2cm).

One thing to notice is how much bluer the hue is. Clearly, you can't go putting a pigment that is as coarse as this on your canvas but it does demonstrate the difference that particle size can make.

When you grind cinnabar down to make a paint, the final results will be larger than the synthetic/ purified version giving the paint a different colour and texture. sectiosn under the microscope will tell the difference and if you are looking at producing something that is original as possible, you don't want to go using something that didn't exist when the original work was produced (this doesn't affect cinnabar/ vermillion on works that are only half a millenium or so old because vermillion has been produced since 4th century BCE in China and around 750 CE in Europe but it does with Lapis Lazuli and French Ultramarine, the former being a rock and the latter being synthesised in 1826 CE)

Just be aware that some people will try to sell you vermilion as cinnabar.

There is no non-zero safe level of mercury so whilst this comes as granules rather than powder, it is still best to handle it wet. Mercury is a neurotoxin.

This is gold powder. It is mixed with a watercolour medium and you paint it on very thinly and when it is dry, you can either leave it as a sparkling semi-matt finish or you can rub the surface with a hard, smooth stone - usually agate - so that the surface of acacia gum is rubbed off leaving the gold which is so malleable that the force from the burnishing stone spreads it over the adjacent gold and fuses it together into a single, flat surface that reflects light as a mirror would.

You can have some gold left untouched and some burnished so as to produce a desirable effect should you so wish. You can purchase burnishing tools in a wide variety of shapes and sizes to achieve just what you want.

The gold-powder water colour paint used to be stored in shells which has given it its name of 'shell gold'.

This is Verdigris pigment. Chemically, it is copper(II)acetate monohydrate and has this lovely turquoise colour.

It is fairly coarse but the crystals are soft and it grinds quite well.

In water colours is was used in the medieval manuscripts and in oils, it was used in the renaissance by Jan van Eyck and so on. In oil, as it dries, it changes hue to a green. It is stable in oil and watercolour as there are plenty of works from over half a millennium to substantiate this.

Copper is used by your body and your liver will be able to take out and store any excess amounts for later use should you ingest any. However, it should be noted that the amount you actually need is only between 2 and 3 milligrammes per day so accidentally ingesting more than about twice that is to be avoided. Like all pigments, this should be treated with respect but it is not one to get paranoid about.

This is Stack Lead White pigment.

The lumps are fairly hard and if you try to break them dry, you will get dust problems.

You need to wet them first - try water. If you are making oil paint with it, grinding in oil isn't a problem as the lead white prefers the oil and leaves the water behind. Of course, you can use oil or oil/turpentine to wet it instead if you want to.

It makes a fine, warm white that has been used for many millennia.

However, there is no safe, non-zero level of exposure to lead so care is required. Lead is a neurotoxin.

don't grind gold - it fuses into bigger lumps - gold doesn't produce an oxide surface so if you force two pieces of gold together using enough force, they will fuse into one piece.

don't put sulphides with copper or lead compounds - both copper and lead go black when in contact with hydrogen sulphide. Note that some sulphides are stable enough to use with lead - for instance, lead white and vermilion are okay because vermilion is stable enough not to release hydrogen sulphide since they were mixed together 600 years ago.

don't make a palette of incompatible paints - if you are going to use paints that are incompatible, use two palettes - I have one for the sulphide-based paints and one for the others.

Remember...

SAFETY FIRST.

Many pigments are toxic to some degree - either in low doses over a long time or in higher doses in a single instance (cronic and acute poisoning respectively) - so, it is important for your own safety and that of those around you to adopt certain practices that will preclude such events.

To contaminate yourself with pigments (or other painting-related compounds), there are a number of routes into your body. The most obvious of these is your mouth. Others include your lungs, skin, nose, eyes and so on. Avoiding activities that allow things to come into contact with these routes is the most effective way of avoiding contamination. So, when painting or preparing pigments, paint, solvent:

Do not smoke. Apart from the obvious fire hazard with organic solvents, you will be putting things in your mouth that you have handled with your fingers;

Do not eat or drink for the same reasons;

Keep your painting related activities in an area that is away from your normal living area (you will be less vigilant when not painting so more likely to become contaminated);

Keep away from pets, partners and children, whether the materials are in current use or not;

Pigments are powders that you can breathe in so keep the dust level down by prevention - when mixing pigments, do things slowly and using as little force as possible thereby reducing the energy that can throw powder into the air.

Do not paint when intoxicated - you will not be as aware of the potential dangers;

Wear protective clothing so that your everyday clothes do not become contaminated - an apron will do, just something that is going to stop whatever it is that you are working with coming into contact with you or your clothes;

If you become aware that you might be breathing in more solvent than is healthy, increase the level of ventilation (if you are gilding, don't do it where there are solvents anyway as you cannot have drafts with such an activity.

Finally, clean up after you have finished. You don't want pigments mixing together but more importantly, you don't want to pick up any contamination from stuff that has not been cleaned away which you can then ingest by accident.

The above is not an exhaistive list. Feel free to be even safer in areas that are not mentioned above as well as those that are.

Back to top

Grinding pigments

If you buy pigments then many of them will already be very fine and really, all you will be using the muller and slab for is mixing them with the medium. However, if you make your own pigments or get pigments that do need grinding finer, you will need a surface that can handle them. On the right are the two surfaces that I use to grind pigments - Marble and Granite. You can also get glass with a ground surface.

Granite is nice and hard so the pigments are less likely to scratch it but if you can't get hold of granite, what can you get away with?

Pigment Hard-
ness Okay with...

Marble Glass Granite

Granite   7

Smalt 6-7 No No Maybe

Glass plate   5.5

Turquoise 5-6 No Maybe Okay

Lapis lazuli 5-5.5 No Okay Okay

Marble   3-5

Malachite 3.5-4 No Okay Okay

Azurite 3.5-4 No Okay Okay

Lead White 3-3.5 Maybe Okay Okay

Chalk 3 Okay Okay Okay

Cinnabar 2-2.5 Okay Okay Okay

Alum* 2-2.5 Okay Okay Okay

Verdigris 1.5 Okay Okay Okay

Egyptian Blue 1-2 Okay Okay Okay

This is a table comparing various materials that your slab can be made from compared to a number of different pigments that you might want to grind. You can see that most of them are fairly soft so a marble slab will do but there is nothing quite like grinding smalt on a marble slab to act as an incentive to find a granite slab.

*Note: Alum is a commonly used substrate that is used to precipitate dyes. This process is necessary because if the dye was not fixed like this it would migrate throughout the medium and not only would it dye other layers in the painting but if dye migrated through an opaque layer such as the painting's ground, you would lose sight of it.

Pigments that are dyes precipitated onto alum include: Indigo/Woad; Alizarin; Rose Madder; Madder Lake and so on. These have a 'gritty' feel to them when you start grinding them but being so soft, it soon smooths out.

This is marble. It is quite pretty to look at but you can see from the table above that it is actually quite soft. This is because it is formed by heating up chalk until it just about melts therefore it has the same sort of hardness as chalk.

If you do start grinding something that is harder than the slab, you will actually be grinding the surface of the slab away and that is what you will end up with in your paint. Smalt provides an excellent example of the damage you can do to a slab by grinding something that is too hard.

Purchasing a glass slab with a ground surface seems to be a particularly difficult thing to do at a reasonable price. I have seen suggestions that you buy a thick (6mm+) piece of glass and then use some carborundum and your muller to grind the surfaceof the glass but that means that you are also grinding away your muller and they are not cheap. A glass slab has a hardness of around 5.5.

This is granite. It was on sale in a city centre shop as marble (so much for the knowledge of the shop's supplier - it was one of many and there were no marble ones so it was not as though someone in the shop had put the wrong label on it or something).

You can see that it is made up from a load of different crystals that have all set together in a single piece and the result of all of these harder minerals is that the resultant rock has a hardness of around 7.

On that, you can grind just about anything you are likely to want to use as a pigment. Even lapis lazuli has a hardness of 5-5.5.

I have ground smalt on a granite slab and it still takes some of the surface away but remember that granite is not a single mineral and there are likely to be softer minerals in it in the interstices of the crystalline structure.

This is a rubberised mat. You will need something like this to stop the slab from moving around on your work surface. If you can't keep the slab from moving, there is a danger that a piece of grit will get under it and start scratching your work surface. Also, if you are grinding your pigments for some time, having the slab move around is just wasting your energy and you will find grinding more tiring than it needs to be.

You can pick these mats up fairly easily and they don't cost very much. Your local supermarket or hardware store is your best bet - I'm sure the art shops would like to sell you something at many times the price.

Here are two different types of muller - the hand-held glass grinder that you will use for grinding your pigments down. They are not cheap but they will last you a long time if you look after them.

This is the muller with the short handle and how you would hold it. You can see that as you move it in a circular motion, the only things that are keeping it in your hand are the ends of your fingers and your thumb. Nothing else. If you have something that takes a lot of grinding, your fingers will get tired earlier in the process with this design.

This muller has a longer handle that fits nicely in your hand and you can push with the heal of your hand and pull with all of your fingers together at the same time. This makes it a lot easier to grind pigments than the shorter of the two.

Just before we get onto individual types of paint, there is still one thing in common with water colours and oils and that is the motion you use to grind them.

If you have paint that you are mixing on the flat slab and you are pressing down with a flat surface such as the underside of the muller, the natural thing for it to do is to spread out and the more you chase it, the more it goes everywhere.

However, there is a way that you can move the muller that keeps pulling the paint back towards the centre of the slab.

If you are right handed and move the muller anticlockwise with an overall circular anticlockwise motion, as shown in the diagram with the purple line, the front edge of the muller picks up paint and drags it towards the centre of the red circle. If you are left handed, do it the opposite way around.

You will still need to use the palette knife every now and then to scrape the paint of the rim of the muller but you shouldn't need to be using it all of the time to collect it from all over the slab until you have finished.

Back to top

Water Colours

In water colours, the medium is normally a vegetable gum and some sort of chemical that makes mixing the solvent with it a lot easier - with water as a solvent, it is normally called a 'humectant'.

Ever since Egyptian times, acacia gum (or gum arabic) has been used and it is fairly easy to get hold of, either in resinous chunks that you have to purify yourself or in powder form. It has many modern uses and is fairly cheap and available - you can source it on the internet very easily.

Normally, acacia honey is used as the humectant and this has some useful properties insofar as: when it has dried out, it turns solid; and, it is readily soluble in water, meaning that when you add water to your block of paint in your palette, it will dissolve quickly and get the gum arabic and the pigment into solution. Some manufacturers of water colours use glycerol which doesn't go solid and as a result, that watercolour never dries out. In fact, unless you make your own watercolours, you don't actually know what is in them.

This is the basic water colour paint kit. It consists of:

Stailness steel spatual - this one is around 200mm long and the flattened ends are around 8mm wide. Curiously, it was called a 'micro spatula' which is a different beastie being around 100mm long hand having ends that are around 4mm wide - you don't need one that small;

half palettes - these little plastic wells are where your paint is going to go and that fits in a special box;

two figure balance - a two figure balance weighs two figures after the decimal place so that is in increments of 10mg;

a poringer - aka 'bain marie', 'water bath', 'double boiler', and probably a lot more. You put your stuff in it and then you put it either in or just above some hot water. This means that if you need to warm up a chemical or mixture that can be damaged if heated to too high a temperature, you can limit the temperature that it is exposed to by putting it in one of these and then putting that in a pan with warm or hot water in it;

acacia honey - this is just some from the local supermarket;

acacia gum - this is powdered but you can buy the raw stuff and filter out the bits yourself using a piece of muslin; and,

pigment.

You will also need:

a grinding slab;

a palette knife;

a muller; and

a ruberised mat to stop slipping on the surface or damage to the surface.

Here, I have weighed out 4g of agacia gum powder into the lid of the container.

Next, weigh into the poringer 10g of water and add 3g of honey and dissolve it. Put that on the saucepan with the water in it - it will warm through fairly quickly

Next, tip the acacia gum into the poringer and stir it. It usually clumps like this but after a few minutes of stirring, it starts to dissolve well enough.

After about 10 minutes, it has pretty much dissolved and you can get on with the rest of the process.

If you were using raw acacia gum, you would filter it through some muslin cloth at this stage, clean the poringer and put it back in there to keep warm.

Weighing out some Egyptian Blue pigment.

This is done into the lid of the pigment jar so I'm not contaminating anything else with the pigment.

Pile of pigment on the grinding slab with a depression pushed into the middle of it, ready for the medium to be added.

You can see that the pigment is quite coarse.

Mixing the medium into the pigment.

You can see that how gritty it is. This is with a few drops of medium added and, just so that I don't add too much, I have also added some drops of water - excess water will evaporate off and that process is how it dries out to make the final block.

Use to palette knife to make sure that it is all incorporated so that it make a homogenous pile of pigment in the middle of the slab.

Grinding the pigment using the muller in a circular motion. When you start doing this, you can hear the gritty bits being crushed between the muller and the slab. As you progress, that gets quieter.

Keep going round and around using the pattern in the section above and the paint will satay away from the edges of the slab.

Breaking the seal of paint between the slab and the muller, using a palette knife. The palette knife is tapered so push it in a little way then slide the muller towards it and it will break the seal. Take your time with this as you don't want to apply so much force that you damage your palette knife.

After a while, you will notice that the paint builds up around the edge of the muller and regardless of how the muller is designed, it doesn't find its way beck beneath the muller.

When this happens, you need to use the palette knife to scrape off the paint from around the edge of the muller and put it on the slab. Whilst you are at it, you can also gather up any other paint on the face of the muller and on the slab, mix them up with the palette knife and put it in a heap in the middle of the slab again.

Also, if the paint starts to get too viscous, just add a few drops of water to it, mix it in and carry on.

Whist you are at this stage, you can also smear the paint across the surface of the slab with the palette knife so that the blade is in contact with the slab and the rest of the blade is at a shallow angle as you can see in the picture.

The purpose of doing this is to see how fine the paint is - how much further you need to go in the grinding process.

You can see that in this instance, as the knife meets larger grains of pigment, it makes the palette knife blade lift up as a whole and you get the lines that run perpendicular to the direction of travel that you can see catching the light. This tells you that there is still more work to be done.

The final half-pan of Egyptian blue watercolour paint.

Once you have finished the grinding, the paint should be fairly thick - about the same as the viscosity of molasses. If it is not as thick as that, just use the palette knife to spread the paint over the surface of the slab to let some evaporate off.

Once it is ready, scrape it up and put it in the half pan. Put this to one side, somewhere that is free of dust, to let it dry out over a few days. You can use it straight away but if you don't need to, just let it dry out.

This is my non-sulphide palette. Like a kid's set of paints you can buy at any supermarket where they have a pot of water, dip the brush in, wet the block of paint and then paint with it, that is what you do here except that here, you are using pigments of your choice, whether they are an ancient Egyptian palette of genuine pigments, a palette that was available to the people that made the medieval illuminated manuscripts or anything else. You palette is the real thing.

The Alizarin and ultramarine is a convenience mixture giving a purple.

The Ultramarine is the modern, man-made version of lapis lazuli. Being transparent, the more you paint on, the darker it gets so the Ultramarine and white is a convenience mixture that gives a standard blue which is quite useful.

This is my sulphide palette. With the exception of the verdigris and minium (which were used in the Lindisfarn Gospels and somehow has managed to survive), all of these pigments are compatible with the sulphur-containing pigments orpiment and cinnabar. Lapis lazuli also is a sulphur containing compound but it seems to be stable enough not to be of concern.

The vergaut is a mixture of orpiment and either woad or as in this case, lapis lazuli (depending upon which recipe you are following). It was used for foliage and so on in illuminated manuscripts as a convenience mixture that brought a bit of stability to the greens which, if you made the mixture on the fly, would vary too much.

The purple is also a convenience mixture of woad and rose madder.

In water colour, only use verdigris on its own. It is a beautiful colour but its copper will blacken with free sulphides and the acetic acid in it will attack carbonate compounds such as azurite, malachite and lead white. You can put a layer of clear medium over the areas of verdigris to stop it interacting with the other colours in the work if you feel you need to.

Back to top

Oil paints

In oils, the medium is usually linseed oil - it has enough of the oil that oxidises in air and cross-links to go solid yet flexible. There are other oils that contain the glycerol esters of those fatty acids but no in as high a concentration so they tend not to be as strong. In fact, the first oil paint was in Afghanistan and the medium in that was poppy oil.

In the fifteenth century, the renaissance started in the north of Europe and the likes of Memling, Van Eyck, Van Der Weyden, got to experiment with the medium - the result of which was that the colours in the paintings were far more saturated than they were in the preferred medium of the time which was egg yolk.

Another advantage was that the paint took several days to dry whereas egg yolk took only minutes and this led to a whole new way of painting. Instead of having to have a set of mixtures of intermediate tints and shades, colour could be mixed in situ. This, in turn, led to a blending of colours that had never been seen before.

Another thing that they did - and this is backed up by research done by the National Gallery (London UK) is that they heat-treated the linseed oil. This meant that the oil took less time for the cross-linking/polymerisation reaction to take place, therefore the painting dried quicker - something like a few days instead of a week or two. This meant that the 'fat over lean' principle - where you put layers of paint only with increasing proportions of oil in them over the previous layers - was an irrelevance.

'Fat over lean' is a principle that you use when you paint in layers where the layers below have not been given enough time to dry properly. Generally, the higher the proportion of oil in a paint, the longer it takes to dry. If you put new paint over a layer that has not dried all of the way through, there is a risk that the new layer will dry before the layer below - especially as it has more access to atmospheric oxygen than the layer below. If that happens, the layer below will continue to dry out but as it does so, it will split the dried out layer above as it shrinks thus producing a craqueleur effect. This can take anything from a few minutes to several weeks to happen and it is different to the craqueleur that you see in old paintings which is down to ageing and not differential drying rates.

Instead, a layer of paint was applied to the painting and then it was allowed to dry all of the way through. As that layer was completely dried, there was no need to have to make a fatter layer to paint on the top of it. If you have a look at the collections of the Van Eyck, Van Der Weyden et al paintings in the National Gallery or whatever is convenient for where you are located, you will see that the paint, heat-bodied linseed oil and all, has survived a good 600 years or so.

This all happened before Leonardo Da Vinci - the person usually credited with inventing oil paints - had even been born.

So, what does an oil paint need to do before you stick a brush in it?

First of all, it has to set so linseed oil is the obvious choice here because of its strength and the fact that it doesn't yellow that much over six centuries. Avoid adding catalysts that change the rate of setting of the oil - these are called 'sicatives' - as they mess around with the oil itself and that can lead to the production of something called 'soaps' which, in the virtually 'geological' timescale of paintings migrate through the oil layers and form 'pustules' that erupt onto the surface of the paintings like little volcanoes. Also, avoid oil that has been treated with alkali as alkali (as does acid) starts of the saponification process.

Of course, an oil paint has to be usable as you squeeze it from the tube - you don't want it all settled to the bottom of the tube whilst you have had it in your drawer or box or standing up in a mug or whatever so if the density of the pigment is not too different to that of the oil, it is fairly likely to stay as a homogeneous mixture. However, if it is substantially heavier, it will settle and form a fairly solid lump. With water colours, you have the advantage of the stored paint being in solid blocks but that isn't practical with oils. So, we can't do anything about the density of the oil but we can make it more viscous. Traditionally, this is done by adding beeswax to the linseed oil but pigments vary and some need to have more wax added that others. So, we need to be able to do something about that.

One thing we can do during the making of the paint is make it less viscous whilst we work on it and we can do this by adding some English double distilled turpentine which can evaporate off at the end. You won't need much and it can help.

So, first thing to do is select your pigment which should be dry and not have any unwanted bits in it.

Unless it is an expensive pigment of which you are only going to make a small bit of to use immediately, you should aim at making a tube's worth or thereabouts - better to be a bit under rather than a bit over so in the middle of a grinding slab that is hard enough for your pigment.

Here, we have some verdigris that I have made myself and it has a hardness of 1.5 so marble with a hardness of 3-5 is a safe choice.

Make a pile of pigment in the middle, keeping the spill away from the edges of the slab. Remember that it is a powder so whilst it is dry, it will be very fluid and therefore you have powder handling problems related to the toxicity of the pigment you are using.

In the middle, make a depression and then put in there some linseed oil of your choice.

If you are making paint for a tube and your pigment is particularly dense, say it is a compound of mercury, lead, cadmium, chromium and so on, you are going to need to adopt strategies that reduce or prevent settling out of the pigment during storage.

One strategy is to not add very much oil and this is something that you should be aiming for anyway. The other is to add something that modifies the viscosity of the paint.

A traditional substance that is added is beeswax.

On the right is a small pot of white beeswax that has been dissolved in double distilled English turpentine. Simply adding solid beeswax to the pigment or pigment-oil mixture would not work because it is simply too hard. Instead, this is one part by volume beeswax to roughly four or five parts double distilled English turpentine.

It was made by putting the beeswax in the jar then filling it up (not all of the way leave around a fifth of it empty) with turpentine. Then, heating it in hot water from an electric kettle (not boiling or you might crack the glass of the jar) that has been poured into a saucepan. By leaving an amount of air - 10-20% - it is possible to shake up the contents of the jar. Let the jar warm through and the beeswax will start to melt and dissolve. Finally, let the wax-turpentine mixture set and it can be stored in the usual conditions for months to years.

Use a palette knife to take a small quantity of of the wax-turpentine mixture which is soft enough to add to the pigment-medium mixture without causing lumps of wax to remain in the paint. The amount you need to be looking at is to make a linseed oil to beeswax mixture of about 9:1. Remember that the wax-turpentine mixture is only a fifth beeswax.

This should mix in really easily because the beeswax has turpentine in it which will loosen up the linseed oil quite a bit. Mix it in well with the palette knife and the turpentine should evaporate out of it - a step that should be fairly complete before you start grinding the paint.

Hopefully, you should end up with a mixture that is like a hard paste - there is so little oil in it that the grains of pigment are held together by a mixture of atmospheric pressure and surface tension - not the wax.

The pigment grains are not little spheres, they are randomly sized and shaped and the sharper bits fit in between the gaps between adjacent grains so that it all fits together rather well - if you put the palette knife in the paint and vibrate it, it will flow yet if you apply a steady force to it, it will tend not to. Clearly, you cannot paint with this so we need to grind this using the muller on the slab. This is identical in operation to grinding water colours and if you feel the need to add any solvent, you can add turpentine instead of water.

Pile up the pigment in one corner of the slab and slice off small amounts of it at a time and grind it with the muller. You will find that the paint 'block' will lose its rigidity and if you have the quantity of oil right, it will become like the paint you get out of the commercial tubes of oil paint except that you know what is in this paint.

As you work you way through the paint, pile up the ground paint and when you have finished, mix it all together with the palette knife to make sure that it is the same all of the way through and that it is the correct consistency.

Once you are happy with it, use the palette knife to put it a bit at a time into a paint tube. Every now an then, hold the tube vertically and tap it gently against the work surface so that the paint goes to the end with the lid and any air that is entrained in the paint works its way to the open end.

When you have finished, the surface of the paint should be a minimum of 1.5 to 2 tube diameters below the rim of the tube.

Between your thumb and forefinger, carefully press the end of the tube flat and try to squeeze out any air that might be left in the tube.

Next, fold over around 5mm of the end of the tube then do so again and again, and when you are satisfied that the end is folded over enough, use a pair of pliers to crimp it flat - being careful not to make a hole in the metal tube with the end of the pliers.

Then, write a label for it with at least the name of the colour on it but you might with to add the date it was made, where the pigment came from, what is in the paint, and so on.

Finally, squeeze a little from the tube onto your finger (you might want to wear a glove or you might not) and smear that paint over the edge of the label like has been done in the photograph, then let it dry. (This is a photograph almost two years after it was made.)

Even though I had heard of this from the literature, it still came as a bit of a surprise to see it for myself and, with something that I had made myself.

The green smear is from the 24^th April 2017, from the freshly prepared paint.

I looked at it and couldn't believe my eyes so I made another smear next to it.

Just to make sure and also get a time scale on this, I repeated it a couple of days later.

you can see that the smears from two and four days are essentially the same hue so this takes only a couple of days to happen.

This is not a peculiarity of making your own paint, it is a peculiarity of verdigris paint and is well documented in the literature.

Here is the paint nearly two years later - still comes out of the tube in a smooth, cylindrical shape without using much pressure.

Works just the same as two years earlier.

Perfect.

Meet the family. You can't get these easily anywhere and you certainly can't get them for the same price. I know what is in these paints because I put it there myself. No secret ingredients, no bulking out pigments or using 'alternatives' - these are all the real thing.

From left to right:
Vermilion; Chrome Yellow; Lead-Tin yellow II; Lead-Tin Yellow I; Home-made Dutch Stack Lead White; Malachite; Home-made Verdigris; and, Smalt.

Back to top

All images and original artwork Copyright ©2019 Paul Alan Grosse.