Oil Bars, Oil Colors & Painting with Mirrors

What artist oil bars are

Artist oil bars (also called oil paint sticks) combine oil pigment with a waxy or fatty binder so the paint can be handled as a solid stick. Once applied, the mark behaves exactly like regular oil paint — it can be brushed, blended, scraped, or layered.

• They create bold, direct marks that are difficult to replicate with brushes alone.
• They can be used for drawing lines, filling forms, and building textured passages.
• They are often paired with tube oils in a single painting workflow.
• Commercial versions include R&F Pigment Sticks and Sennelier Oil Sticks.

Oil bars vs tube oils

How to make your own oil bars

Making DIY oil bars is a rewarding studio practice that lets you control pigment load, hardness, and color precisely. The process involves melting a wax blend, incorporating oil color, and casting into molds.

Ingredients

• Beeswax — provides the main structure and body of the bar.
• Linseed or safflower oil — adds flexibility and slows setting; use 10–20% by weight.
• Microcrystalline wax (optional) — firms the bar for warm studios; use sparingly.
• High-quality oil paint or dry pigment — aim for 40–60% pigment load for intensity.
• Stand oil or sun-thickened oil — improves flow and adhesion.

Step-by-step process

1. Melt beeswax in a dedicated double boiler at low heat (never over open flame).
2. Add linseed oil once the wax is fully liquid; stir to combine.
3. Remove from heat and let cool to a thick, pourable consistency (around 60–70 °C).
4. Stir in oil paint or pre-mulled pigment until the color is fully incorporated and uniform.
5. Pour into silicone molds or rolled paper tubes; cool at room temperature.
6. Cure the finished bars for 24–48 hours before use to let the wax set fully.
7. Label each bar with the pigment name and batch date.

Troubleshooting

• Bar too soft: add more beeswax or microcrystalline wax.
• Bar too hard / waxy feel: reduce wax ratio or add more oil medium.
• Color too pale: increase pigment load or switch to artist-grade tube paint.
• Crumbling bar: oil-to-wax ratio is off — increase the oil component slightly.

Oil colors: building your palette

Oil colors are pigments suspended in a drying oil (most commonly linseed, walnut, or safflower). The slow drying time — days to weeks — allows for extended blending, glazing, and reworking that no other medium can match.

A practical starter palette

Most painters can mix any color from a limited palette. Start here and expand only when you identify a specific gap:

Oil color binders and drying times

• Linseed oil — most common binder; slight yellowing over time, best avoided for blues and whites.
• Safflower oil — less yellowing; used for whites and light colors.
• Walnut oil — minimal yellowing, slightly slower to dry, very pleasant to use.
• Poppy oil — slowest drying; maximum open time but increases cracking risk in thick layers.

History: painting with mirrors and the Old Masters

The use of mirrors and optical devices in painting is one of the most debated topics in art history. From concave mirrors to camera obscura setups, many of history's greatest painters are now believed to have used optical aids as part of their practice.

The Hockney–Falco thesis

In 2001, artist David Hockney and physicist Charles Falco proposed that many Old Masters — including Jan van Eyck, Vermeer, Caravaggio, and Ingres — used concave mirrors or lenses to project images onto their canvases, which they then traced. The evidence includes:

• Unusually accurate foreshortening and perspective in works from the early 15th century onward.
• Optical aberrations in painted chandeliers and round objects that match lens projection, not freehand observation.
• Sudden improvements in anatomical accuracy coinciding with the spread of quality glass mirrors in the Netherlands.
• Period documents referencing "mirrors" as tools in artist workshops.

Vermeer and the camera obscura

Johannes Vermeer (1632–1675) is the most studied case. Researchers found that his paintings contain optical characteristics consistent with a camera obscura — a darkened room with a small hole or lens that projects a scene onto a surface. Evidence includes:

• Circles of confusion (soft, out-of-focus halos around bright objects) matching lens projection.
• Consistent perspective across multiple paintings suggesting a fixed viewpoint device.
• A near-perfect scale reconstruction of his studio showing a camera obscura setup would have been feasible.

Importantly, this does not diminish Vermeer's genius — capturing, composing, and painting from a projected image still requires extraordinary skill. The mirror or lens was a tool, not a shortcut.

Verre églomisé: painting on mirrors

Separate from optical aids, verre églomisé is the technique of painting on the reverse side of glass or mirror. Popular from the 17th century through the 19th century, especially in China and later in Europe, it involves:

• Applying paint (often oil or lacquer) to the back of a sheet of glass or silvered mirror glass.
• Working in reverse — the final image is seen through the glass from the front, so detail must be painted first and background last.
• Chinese reverse glass paintings (18th–19th century, produced for the European export market) are among the finest surviving examples.
• The technique creates a uniquely luminous quality as light reflects from the silver layer behind the paint.

Using mirrors in the modern studio

Contemporary painters still use mirrors for several practical purposes:

• Checking compositions: viewing a painting in a mirror reverses it, revealing compositional imbalances that familiarity hides.
• Self-portrait work: a mirror is the traditional self-portrait tool, from Rembrandt to Frida Kahlo.
• Small convex mirrors: used to compress a wide scene into a single small viewing field — the same tool Jan van Eyck depicted in the Arnolfini Portrait (1434).
• Reducing glasses: a darkened convex mirror (Claude glass) used by 18th-century landscape painters to simplify tonal values in a scene.

Technique workflow for better results

1. Prime your surface with a toothy ground so oil bars and paints grip cleanly.
2. Block major shapes with neutral values before introducing saturated color.
3. Use a bristle brush or silicone tool to soften selected edges from oil bar marks.
4. Alternate oil bar passages and tube-oil glazes for depth and variation.
5. Let lower layers set up before heavy reworking to avoid muddy color.
6. Check your composition periodically in a mirror to catch imbalances early.

Safety and studio care

• Use proper ventilation when heating waxes or working with solvents.
• Wear gloves when handling pigments that may be skin irritants (cadmiums, lead white).
• Do not use food cookware for art materials; keep dedicated tools.
• Dispose of oily rags in a sealed metal container to reduce fire risk (linseed oil rags can self-ignite).
• Check pigment safety data sheets and avoid inhaling dry pigment dust.
• Store oil bars and wax mediums away from heat sources.

Related digital tools for painters

When you photograph or scan your oil paintings for print or social publishing, get the resolution right before export:

• DPI/PPI calculator — check if your photo is sharp enough to print at the size you want.
• Pixels to print size — find out how large you can print from your camera or phone image.
• Resolution scale calculator — scale your painting image to any output size without guessing.