There’s a unique satisfaction in understanding your materials from the ground up, quite literally when it comes to making your own oil paints. While convenient tubes dominate the market, grinding your own paints offers unparalleled control over consistency, texture, and pigment load. It connects you to a tradition stretching back centuries, giving you insight into how the Old Masters achieved their luminous effects. It might seem daunting, but with the right materials and a bit of patience, creating bespoke oil colours is well within reach for the dedicated artist.
Gathering Your Core Ingredients and Tools
The fundamental components of oil paint are surprisingly simple: dry pigment and a drying oil, typically linseed oil. The magic happens in how these two are combined. You’ll also need a few specific tools to do the job properly.
Pigments: The Soul of Colour
Pigments are finely ground coloured powders. They can be sourced from various origins:
- Earth Pigments: Ochres, Siennas, Umbers. These are naturally occurring minerals, generally stable, lightfast, and relatively inexpensive. They often have subtle, beautiful tones and are excellent starting points.
- Mineral Pigments: Derived from specific minerals, sometimes requiring more processing. Examples include Ultramarine (historically from Lapis Lazuli, now mostly synthetic) or Viridian.
- Synthetic Pigments: Chemically manufactured pigments. This category includes modern colours like Phthalocyanines and Quinacridones, known for their high tinting strength and vibrancy, as well as historical synthetics like Prussian Blue.
When sourcing pigments, look for reputable artist suppliers. They will provide information on the pigment’s origin, lightfastness, and any safety concerns. Always handle dry pigments with care. They are fine powders that can become airborne easily. Working in a well-ventilated area and wearing a dust mask is crucial, especially when starting out.
Linseed Oil: The Binder
Linseed oil is the traditional binder for oil paints because it’s a ‘drying oil’. This doesn’t mean it evaporates like water; instead, it undergoes a chemical reaction with oxygen (oxidation) to polymerize, hardening into a durable film that locks the pigment particles in place. Several types are available:
- Cold-Pressed Linseed Oil: Considered the highest quality by many purists. It’s extracted without heat, retaining natural impurities that some believe enhance handling. It tends to yellow slightly more over time than refined oils.
- Refined Linseed Oil: Processed to remove impurities. It’s paler and has a more consistent drying rate. This is the most common binder found in commercial tube paints.
- Stand Oil: Linseed oil that has been polymerized by heating in the absence of oxygen. It’s thicker, yellows less, and creates a smooth, enamel-like finish. It dries more slowly.
For beginners, a good quality refined linseed oil is a reliable starting point. You can experiment with others as you gain experience. While linseed is standard, other drying oils like walnut oil (paler, dries slightly slower) or poppy oil (very pale, slow drying, less durable film) can also be used, particularly for lighter colours where linseed’s yellowing might be a concern.
Essential Tools
You don’t need a complex laboratory setup, but a few specific tools are non-negotiable for effective paint grinding:
- Glass Muller: A heavy, flat-bottomed glass tool with a handle. The weight of the muller does most of the work. The base is usually frosted or sandblasted slightly to provide a ‘tooth’ that helps disperse the pigment.
- Grinding Slab: A thick, flat surface. Tempered glass (at least 1/4 inch thick, with smoothed edges) is ideal because it’s non-porous and easy to clean. Granite or marble slabs can also work, but they might be slightly porous depending on the finish. The slab should be larger than the diameter of your muller’s base to allow ample room for grinding.
- Palette Knives: Flexible metal spatulas are essential for gathering the pigment, mixing the initial paste, and scraping the slab and muller clean. Have a couple of different sizes/shapes handy.
- Storage Containers: Empty paint tubes are the professional standard, though they require a crimping tool. Small glass jars with tight-fitting lids work well for storing small batches initially. Syringes (without needles) can also be used for short-term storage and easy dispensing.
The Art of Grinding: Step-by-Step
Grinding paint isn’t about crushing the pigment particles smaller; they are already finely powdered. The goal is dispersion – thoroughly coating every single particle of pigment with the oil binder. This creates a smooth, homogenous paste with optimal colour development and handling properties.
Preparation is Key
Set up your grinding station in a well-lit, well-ventilated area away from food preparation. Ensure your glass slab is perfectly clean and dry. Put on your dust mask and gloves before opening any pigment containers. Lay out your pigment, oil, muller, and palette knives.
Making the Initial Paste
Place a small amount of dry pigment onto the center of your slab. Don’t start with too much; it’s easier to manage smaller batches. Use your palette knife to form a small indentation or ‘well’ in the middle of the pigment pile. Carefully pour a small amount of linseed oil into the well. Start with less oil than you think you’ll need – you can always add more, but removing excess oil is difficult.
Use the palette knife to gently incorporate the oil into the pigment. Work from the outside in, folding the pigment over the oil. Gradually mix until you form a stiff, crumbly paste. The consistency should resemble thick putty or dough. If it’s too dry and powdery, add a tiny drop more oil. If it seems too oily already, try incorporating a little more pigment if you have spare.
Grinding with the Muller
Gather the paste into a mound in the center of the slab. Place the glass muller onto the paste. Now, begin moving the muller in a steady, overlapping pattern. A wide circular motion or a figure-eight pattern works best. Apply moderate, even pressure – let the weight of the muller do most of the work. You’re not trying to pulverize the pigment, but to shear the pigment particles apart and ensure each one is coated in oil.
You’ll hear a distinct gritty sound initially. As you continue grinding, this sound should lessen, and the paint will become smoother and possibly more fluid. Use your palette knife periodically (every few minutes) to scrape the paint that accumulates around the edges of the slab and under the muller back into the center. This ensures all the paint gets evenly ground.
The grinding time varies significantly depending on the pigment. Some earth colours might come together relatively quickly (15-20 minutes), while some finer synthetic pigments might require significantly longer (45 minutes or more) to achieve optimal dispersion. Judge readiness by texture and consistency. The paint should feel smooth under the muller, not gritty. It should have a satisfying ‘short’ texture – meaning it breaks cleanly when pulled with a palette knife, rather than being long and stringy.
Handle Dry Pigments Safely! Many traditional and modern pigments carry health risks if inhaled or ingested. Always wear a NIOSH-approved dust mask when handling dry powders. Work in a well-ventilated space and wear gloves to avoid skin contact, especially with heavy-metal pigments like cadmiums or cobalts. Clean up spills promptly and avoid eating, drinking, or smoking in your workspace.
Adjusting and Testing
As you grind, you might need to adjust the consistency. If the paint becomes too stiff, add another tiny drop of oil and grind it in thoroughly. If it seems too loose or oily, you might have started with too much oil. The ideal consistency is often described as being like cool butter. Test the paint by spreading a thin layer with your palette knife – look for smoothness and vibrant colour.
Beyond the Basics: Refining Your Paint
Once you’ve mastered the basic technique, you can explore further nuances.
Pigment Characteristics
You’ll quickly discover that each pigment behaves differently. Some pigments, like Alizarin Crimson or Phthalo Blue, are notoriously thirsty and require a larger proportion of oil relative to pigment volume. Others, like lead white (handle with extreme caution due to toxicity) or some earth colours, require much less oil to form a paste. Experience is the best teacher here. Keeping notes on pigment-to-oil ratios for colours you make frequently can be very helpful.
Optional Additives
While pure pigment and oil make excellent paint, sometimes additives are used to modify properties:
- Waxes (e.g., Beeswax): Can be added in very small amounts (melted into the oil first) to impart a more buttery or matte quality. Too much can affect the film strength.
- Stearates (e.g., Aluminum Stearate): Often used in commercial paints to prevent pigment and oil from separating during storage and sometimes to bulk up the paint. Use sparingly, as overuse can lead to a weak paint film.
For beginners, it’s best to focus on mastering the pigment and oil relationship before experimenting extensively with additives.
Storing Your Hand-Ground Paint
Once ground, scrape the finished paint carefully into your chosen container using the palette knife. If using tubes, fill them from the bottom, leaving space to fold and crimp the end securely. If using jars, press a piece of plastic wrap or wax paper directly onto the surface of the paint before sealing the lid to minimize contact with air, which will start the drying process.
The Rewards of Hand-Crafted Colour
Making your own oil paint is more than just a novelty. It provides a deeper connection to your medium. You gain precise control over the pigment load – often achieving richer, more saturated colour than typically found in student-grade or even some artist-grade tubes where fillers might be present. You can tailor the consistency exactly to your liking, from stiff impasto paints to more fluid glazing colours.
There’s also a potential cost saving, particularly if you use large quantities of expensive pigments like Cobalts or Cadmiums, as buying them dry and grinding them yourself can sometimes be more economical than purchasing equivalent high-quality tubes. Above all, it fosters a profound appreciation for the substance of paint itself, transforming it from a mere commodity into a personally crafted medium full of potential.
