Chalk pastels have the look and feel of chalk, but are softer and brighter.
Having the proper paper for chalk pastels is important so you can achieve the best results. There are many potential papers to choose from, and all artists have different preferences. However, there are various types to look for when working with chalk pastels, or sticks of powdered pigment that are held together with a binder. Chalk pastels are soft and easy to apply, making them appealing for artwork, especially fast work.
Textured Paper
When an artist uses a pastel stick on paper, it leaves behind a fine powder, which is the pigment that forms the stick and gives pastel its defining look. This effect is harder to achieve with smooth papers, so an ideal paper for chalk pastels has some texture to it. The texture not only helps to grind away small amounts of pigment from the stick, but it helps to hold the pigment to the paper. Watercolor paper, although not designed for pastels, is often textured enough to be suitable for use with pastels.
Acid-Free Paper
Though paper can be made from any plant fiber, most papers are made from wood pulp, which is acidic. Acidic paper degrades and becomes brittle over time, which is a problem for artwork. Thus, art paper needs to be acid-free, especially when dealing with chalk pastels. Acid-free paper has a pH of around 6 or 7, so some papers labeled "acid-free" are slightly acidic. Similar to acid-free papers, there are also "conservation-grade" and "museum-grade," or "archival," papers. "Conservation-grade" papers are acid-free, made from wood pulp and contain chemicals that act as pH buffers. If a paper is labeled "archival" or "museum-grade," it is made from cotton, which contains no acid. Papers made from linen and rag also have low acidity.
Lignin-Free Paper
Lignin is a chemical found in wood. In a plant, its purpose is to hold the plant fibers together. In paper, it creates a tan hue that can be attractive and desirable. However, lignin deteriorates, becoming brown or yellow and acidic over time. High-quality art papers have the lignin removed chemically to prevent this eventual deterioration. Cotton and linen papers naturally have low or no lignin, and for chalk pastel use, this is very important. The appearance of chalk pastels change depending upon the paper, so a white paper that becomes yellowed will permanently alter an image.
Other Considerations
While the most durable, longest-lasting and most suited paper for chalk pastel is paper made from cotton, linen or high alpha cellulose -- or wood pulp with long, durable fibers -- there are many reasons why you would not want to use such a paper. For instance, chalk pastel is typically used as a sketching medium, and using high-quality paper is unnecessary for sketches. Rough papers are more efficient, but smooth papers result in a smoother appearance. Chalk pastels also have interesting effects on colored papers. Because different kinds of paper yield such different results, artists who work with them often experiment with many different kinds of surfaces to get the desired look.
