What is the difference between soft pastels and oil pastels?

What are the chemical differences between them?

Soft pastels are composed primarily of dry, powdered pigment with a small amount of gum binder, such as gum tragacanth. Because they contain very little binder, they feel like pure chalk and produce a vibrant, velvety finish. They are inherently fragile and prone to smudging, as the pigment sits loosely on the surface of the paper. Artists often use them for delicate layering and painterly effects that mimic charcoal or chalk drawing.

Oil pastels, by contrast, are formulated with pigment, a non-drying oil, and a wax binder. This composition creates a stick that feels similar to a crayon but with a much higher pigment load and a buttery consistency. Unlike soft pastels, they do not dry out or dust off the page once applied. They remain workable for a longer period, allowing artists to manipulate the medium on the surface with tools or fingers long after the initial application.

How to use soft pastels effectively

Soft pastels are best applied to "toothed" papers, such as sanded pastel paper or textured cardstock, which grip the loose powder. Beginners should start by layering light colors over dark ones, as the medium can quickly become muddy if over-blended. Because the pigment is loose, you must handle your work carefully to avoid accidental smearing or pigment loss.

1. Select a high-quality, textured paper to ensure the pigment adheres properly.
2. Apply light pressure to lay down the initial color, then build up layers gradually.
3. Use a blending tool or your finger to soften edges, but avoid over-working the surface.
4. Apply a professional-grade fixative spray in a well-ventilated area to secure the finished drawing.

Avoid the common mistake of using smooth paper, which cannot hold the pastel dust, causing the pigment to slide off the page entirely. Additionally, do not apply fixative too heavily, as it can darken the colors and flatten the texture of the drawing.

How to use oil pastels for painting

Oil pastels function more like a painting medium than a drawing tool. You can apply them directly to paper, canvas, or wood, and they do not require a fixative to remain permanent. Because they are oil-based, you can thin them with turpentine or mineral spirits to create wash-like effects, or use a palette knife to scrape back layers for a textured, impasto look.

• Use a stiff brush dipped in mineral spirits to blend colors into a smooth, paint-like finish.
• Layer colors by applying pressure to create thick, opaque passages.
• Scratch into thick layers with a needle or knife to reveal colors underneath, a technique known as sgraffito.
• Mix colors directly on the substrate by overlapping strokes and blending with a dry cloth.

Avoid using paper that is too thin, as the oil content can eventually seep through and create grease spots. Always ensure your surface is primed with gesso if you are working on wood or canvas to prevent the oil from degrading the material over time.

Which medium is best for beginners?

Choosing between these mediums depends largely on your personal preference for cleanliness and texture. Soft pastels are ideal for those who enjoy the tactile nature of drawing and want to achieve soft, atmospheric transitions. However, they are notoriously messy and require a dedicated workspace to manage the airborne dust. If you are sensitive to dust, you may find the powdery nature of soft pastels challenging to manage in a home studio.

Oil pastels are generally more accessible for beginners because they are portable, clean, and require no special fixatives. They are excellent for those who want to experiment with bold, vibrant colors and thick, expressive marks. Because they do not smudge once applied, they are easier to store and transport. If you prefer a medium that feels like a cross between a crayon and an oil paint, oil pastels offer a more forgiving and durable entry point into color work.

Common mistakes when working with pastels

One of the most frequent errors with soft pastels is "filling the tooth" of the paper too early. Once the surface texture is completely covered with pigment, the paper can no longer hold additional layers, leading to a slippery surface where new strokes fail to stick. To avoid this, work from thin to thick and save your final, most intense highlights for the very last stage of the drawing process.

For oil pastels, the most common mistake is applying too much pressure too soon, which can clog the surface and make further blending impossible. Beginners often try to blend colors that are too similar in value, resulting in a dull, greyish appearance. Instead, focus on layering contrasting colors and using a solvent to move the pigment across the surface. By understanding the specific requirements of each medium, you can ensure your artwork remains vibrant and structurally sound for years to come.