Are pastels chalk?
That is a question commonly asked of any pastelist. The short answer is "no". And here is the long answer:
Natural chalk is actually a form of calcium carbonate - the same mineral as limestone, but in a much softer form and is quarried like any other stone. Blackboard chalk, which is what most have in mind when they ask this question, was traditionally made from the quarried stone but is now a manufactured material made of colored calcium sulfate. It is both hard and crumbly in consistency and the colors are not very saturated.
Pastels on the other hand are almost pure pigment - the same pigments used in oil, acrylic, watercolor and other paints. The pure, powdered pigments are mixed with a minimal amount of binder, traditionally gum arabic, to make a paste which is shaped or extruded into stick form and dried. Harder pastels have more gum and softer pastels have less, but all pastels have far less binder than paints. This means that the colors are more saturated than any other media, and will retain their saturated color over time. Unlike oils, they will not yellow or darken due to oxidation or crack or craze due to shrinkage. Pastels painted centuries ago are still as vibrant as they were when first painted.
There are however, other issues with pastels. There is a perception that they are fragile in nature and will flake and fall off their support. In the past, artists were unaware of the need for acid free support. Many Degas paintings are displayed in low light, controlled environments in glass cases. This is not because of the pastels but rather because the paper he used was not acid free and is slowly degrading and will eventually simply fall apart. Modern artists, myself included, are now careful to use only acid free material to ensure that their paintings last over the years.
Additionally, pastels must be protected behind glass. Because they are a dry medium, the pigments are simply sitting on the support rather than permanently bonding with it. While this allows the artist to blend the pigments, it also means that they are vulnerable to accidental smearing. Some artists use spray fixative as a solution, however this tends to both dull and darken the pigments and is usually avoided in the final layers. But even without fixative, the pigments will not just fall off the paper. All supports have a texture, or tooth, that the pastel will adhere to and will not easily be removed as any pastelist attempting to make dramatic changes will testify.
So are they paintings or drawings? Because pastels are a dry medium and are most often on paper, they are often categorized by non-pastelist as drawing. Many art shows and competitions lump them in with charcoal, ink and pencil. If the use of the pastel is minimal and paper shows through most of the work, it is generally considered a drawing. However, if the pigments cover most or all of the paper and the pastel is laid down in multiple layers, it is considered a painting. In short, if it looks like a drawing, it's a drawing and if it looks like a painting, it's a painting. Most pastelists work in such a way that they consider their works to be paintings. Personally, I consider most of my pastel work to be painting.
Pastels, despite having been around for hundreds of years (they were actually developed by Leonardo DaVinci) and despite their extensive use by masters such as Degas, have been largely dismissed as "studies" and "sketches" within the mainstream art world. However, in recent years the number of pastelists had increased dramatically, and pastel paintings are well on their way to being recognized as the "high art" form that they are.