For most of oil painting’s history, there were no paint tubes, no factory-made sets, and no premixed “Titanium White” ready to squeeze. Paint was a workshop product, prepared by apprentices and assistants, or by the artists themselves.
The core process was simple in concept but demanding in practice:
The quality of the paint depended on everything: how pure the pigment was, how finely it was ground, how much oil was used, and how carefully it was dispersed. In other words, the “feel” and look of old master paint began long before it touched a canvas.
This article walks through that historical process: from pigment to paste, the tools used, typical ratios, and what we know from modern reconstructions.
Traditional oil paint was fundamentally just pigment + drying oil.
Pigments were insoluble powders that provided color. Historical sources include:
Some pigments have since become obsolete due to toxicity or stability issues.
Pigments often arrived as coarse powders or lumps and sometimes had to be further ground and levigated (washed to sort by particle size) before oil was added.
The primary binder was linseed oil—the pressed oil of flax seeds. This same plant provided fibers for linen canvases. Analyses of old paintings and historical accounts show that artists also used walnut oil and, less commonly, poppy or other oils, but linseed dominated due to its drying speed and film strength.
In its simplest form, historical paint was:
No resins, waxes, or dryers—those came in later recipes and varnishes.
Historical sources and reconstructions show that making paint was often part of a broader studio workflow.
Apprentices and assistants prepared panels, canvases, and pigments, and ground paint. Masters focused more on design, drawing, and final layers, but many also supervised or participated in paint preparation.
A 17th-century engraving, for example, shows assistants placing red earth on a stone slab, adding linseed oil in small increments, and grinding with a stone tool. The process could be laborious, especially for pigments that were hard to wet or disperse.
Paint might be:
The essential tools for making traditional oil paint were remarkably minimal and have changed little when compared to modern hand-grinding setups.
Historically:
The surface had to be:
Modern guides recommend preparing glass slabs and mullers by grinding silicon carbide (carborundum) into them until they look evenly frosted.
A muller is a hand-held grinding tool with a smooth, flat bottom and a handle. Historically, these were made from:
The muller provides shear force, pressing the pigment-oil mixture against the slab and distributing the pigment evenly through the binder.
Even with a muller, palette knives or scrapers played a crucial role:
Historical assistants likely used metal spatulas or similar tools; modern practice uses stainless steel knives.
Reconstructed historical methods and modern hand-grinding instructions agree on the core process.
If pigment arrived coarse or contaminated:
On the slab:
Historical sources and modern practitioners emphasize: do not start with too much oil. It is easier to add oil later than to correct an overly runny mix.
Once a rough paste exists:
Modern guides describe a “rhythm” of mulling, scraping, and regathering, often repeating this cycle for several minutes or more depending on pigment difficulty. A video reconstruction of historical methods notes that mulling converts that stiff paste into a smooth, buttery paint, fully dispersing pigment into the oil.
After initial grinding:
Different pigments absorb different amounts of oil. For example, one technical source suggests approximate ratios by weight such as:
The guiding principle: add only enough oil to wet the pigment and create a paste at the desired stiffness.
Paint-makers historically (and now) test:
If the paste passes these tests, it can be used immediately or stored.
Before the mid-19th century invention of the paint tube, storing oil paint was tricky.
Historical methods included:
Because storage was imperfect and drying slow but continuous, many artists preferred to grind paint fresh (especially certain colors), ensuring perfect consistency and minimal separation. With the advent of tubes in the 1800s, industrially ground paints could be made more consistently and preserved longer, revolutionizing studio practice.
While the basic recipe was pigment + oil, historical and early modern artists experimented with additions:
Modern analysis of old masters suggests that, despite centuries of recipes claiming lost secrets, many great works relied on relatively simple oils and straightforward methods, while more complex mediums became common later.
Not all pigments grind the same way in oil.
Ultramarine blue, for instance, is noted as one of the more difficult pigments to disperse; it can get stringy or require more oil, depending on grade and oil type. Paint-makers developed experience with each pigment’s behavior, adjusting grinding time and oil proportion accordingly.
You can mix pigment and oil roughly with a palette knife and get something that looks like paint, but proper grinding ensures:
Modern practitioners emphasize that the muller provides the shear needed to bind pigment particles thoroughly; simply stirring may leave agglomerates partially dry inside. This is why a modest-sized muller and properly prepared slab are recommended for serious hand-made paint—even today.
Historically, many pigments (lead, arsenic-based, mercury-based) were toxic, and awareness of health risks varied. Today, anyone attempting historical methods should follow modern safety practices:
Modern guides stress careful handling, especially during the dry pigment stage, which is when inhalation risk is highest.
Even in an age of excellent commercial paints, some artists choose to grind their own colors. Reasons include:
Some craftspeople making linseed oil paints for woodwork embrace similarly simple formulations: raw linseed oil and natural pigments, with no added synthetic binders or dryers, echoing older traditions.
A contemporary, historically-informed workflow for making a small batch of oil paint might look like this:
Prepare tools: Frosted glass or stone slab; Glass or stone muller; Palette knife, scraper; Refined linseed oil; Pigment (e.g., yellow ochre, ultramarine).
Measure pigment: Optionally weigh pigment and oil for repeatable ratios (e.g., starting around 70–75% pigment to 25–30% oil).
Initial mixing: Pile pigment on the slab; add a small well of oil. Fold together with knife until you have a stiff paste.
Mulling: Press the muller onto the paste and move in circles, figure-eights, and small arcs. Spread the paint out thinly and work it across the slab. Periodically scrape the paint back to the center and repeat for several minutes.
Adjust: If too stiff, add a drop or two of oil and mull again. If too runny, sprinkle in more pigment and mull until smooth.
Test: Brush a small stroke on a test panel to check consistency, opacity, and flow. If satisfactory, collect the paint with a knife and store in a small jar or use immediately.
This is essentially the same process assistants in historical workshops would have followed, though their tools might have been stone rather than glass and their pigments mined or processed by hand.
Historical and modern sources pay attention to oil quality:
Today, some artists enjoy the romance of refining their own cold-pressed linseed, while others note that well-made commercial refined linseed oil often provides superior, more predictable performance: less yellowing, tougher film, good wetting of finely divided pigments. In either case, the balance between pigment and oil and the thoroughness of grinding remain central to paint quality.
Research into old masters suggests that early oil painting often used relatively straightforward oils as binders, sometimes bodied or combined with modest resin additions. Over time:
Modern conservation work indicates that many of these complex recipes were likely not the basis of earlier masterpieces, which often relied on more direct techniques with linseed and walnut oils. Nevertheless, the “secret medium” tradition attests to how much artists valued control over drying, gloss, and handling.
Even if you never grind a single pigment yourself, knowing how paint was historically made can:
When you open a modern tube of oil paint, you’re benefiting from the same basic chemistry and craft that assistants on stone slabs practiced hundreds of years ago, simply industrialized and standardized.
Reliable flow and authentic mixing behaviors designed for technique development, studio training, and bold experimentation.
Maximum pigment loads, verified single-pigment purity, and premium binders engineered for permanence.
