Learning how to sharpen pastel pencils is one of those things that seems simple until you actually try it and end up with a pile of broken pigment in your trash can. It's honestly one of the most frustrating hurdles for new artists. You spend good money on a set of professional pencils, only to watch half the lead snap off the moment you apply any pressure.
The reason this happens isn't usually because you're being clumsy. It's because pastel pencils are a completely different beast compared to standard graphite or even colored pencils. The core is made of compressed pigment and binder, which is naturally brittle. If you treat it like a regular pencil, you're going to have a bad time.
Why standard sharpeners usually fail
We've all been tempted to just shove a pastel pencil into a standard electric or manual crank sharpener. It's fast, it's easy, and it's what we've done since elementary school. But with pastels, that's usually a recipe for disaster.
Most office sharpeners work by "grabbing" the pencil and rotating a blade around it. This puts a lot of torque on the core. Because the pastel core doesn't have the same structural integrity as graphite, it just snaps under the twisting pressure. Even worse, the abrasive nature of the pastel can dull those blades in record time. Once the blade is dull, it starts dragging instead of cutting, which—you guessed it—leads to more breakage.
If you really want to use a mechanical sharpener, you need one specifically designed for soft cores, like a Dahle 133 or a dedicated pastel sharpener. But even then, there's a learning curve. For most of us, the manual approach is much safer and results in a better point for our artwork.
The craft knife and sandpaper method
If you ask ten professional pastel artists how to sharpen pastel pencils, at least eight of them will tell you to use a knife. It sounds intimidating if you haven't done it before, but it gives you the most control. You aren't putting any twisting pressure on the core, and you can expose as much or as little of the pigment as you need.
Start with a sharp utility knife or a specialized hobby knife like an X-Acto. Hold the pencil in your non-dominant hand and the knife in your dominant one. Instead of "whittling" like you're making a spear, use your thumb to gently push the back of the blade. You're shaving away thin slivers of the wood casing, moving away from your body.
The goal here isn't to sharpen the pigment with the knife. You're just trying to expose about half an inch of the pastel core. Once you have a nice "cylinder" of pastel sticking out, put the knife down. This is where the sandpaper comes in.
Using a sandpaper block (you can buy these at any art store, or just use a piece of fine-grit sandpaper from the hardware store), gently rub the pastel core against the surface. Rotate the pencil as you go. This allows you to create a lethal, needle-like point without the risk of the core snapping off inside a sharpener. It's therapeutic once you get the hang of it, and it saves so much of your expensive material.
Choosing the right manual sharpeners
I get it—not everyone wants to carry a knife around or spend five minutes sharpening a single pencil. Sometimes you're in a flow and you just need a quick point. If you want a manual handheld sharpener, you have to be picky.
Look for sharpeners with high-quality, replaceable steel blades. Brands like M&R or Kum make brass sharpeners that are much better suited for this. The trick when using a handheld sharpener is to move the sharpener and not the pencil.
Hold the pencil still and slowly rotate the sharpener around it. This reduces the amount of torque being applied to the delicate core. Also, don't try to get a "factory point" every time. As soon as you feel any resistance or hear a "crunchy" sound, stop. You're better off finishing the point with a quick swipe on some sandpaper than pushing your luck and having the tip snap off inside the blade.
Dealing with internal breakage
Sometimes, you can be as careful as a surgeon and the tip still falls out every time you sharpen it. This is usually due to "internal breakage." Pastel pencils are fragile, and if they've been dropped on a hard floor—either at your house or during shipping—the core can shatter inside the wood casing.
It's heartbreaking, but it doesn't always mean the pencil is garbage. If you suspect internal breaks, try using the knife method exclusively. By removing the wood casing very gently, you might be able to "rescue" the broken chunks of pigment and use them for broad strokes or underpaintings.
One "old school" trick some artists swear by is putting the pencils in a warm spot (like a sunny windowsill) for a bit. The idea is that the binders might soften slightly and "re-bond," though this is hit-or-miss depending on the brand. The best cure is prevention: treat your pastel pencils like they're made of glass. Don't let them roll off the table!
The importance of a clean blade
Pastel is dusty, and that dust gets everywhere. When you're figuring out how to sharpen pastel pencils effectively, you have to keep your tools clean. The wax and pigment from the pencils can build up on your knife blade or the sharpener's cutting edge.
When this buildup happens, the blade loses its "bite." Instead of slicing through the cedar wood, it starts to push against it. That extra pressure is exactly what causes the core to snap. Every few pencils, wipe your knife blade down with a bit of rubbing alcohol or just a dry cloth. If you're using a manual sharpener, use an old toothbrush to flick out the packed dust from the corners of the blade. It makes a world of difference.
Adjusting for different brands
Not all pastel pencils are created equal. If you're using Pitt Pastels by Faber-Castell, you'll notice they feel a bit "harder" and can usually handle a standard sharpener a bit better. On the other hand, if you're using Caran d'Ache or Stabilo CarbOthello, those cores are much softer and more "chalky."
You'll need to adjust your technique based on what's in your hand. The softer the pencil, the more you should lean toward the knife and sandpaper method. It takes a little more patience, but when you're trying to get those fine details in a portrait—like individual hairs or the glint in an eye—having a perfectly tapered point that doesn't crumble the second it touches the paper is worth the effort.
Keeping your workspace tidy
Lastly, let's talk about the mess. Sharpening pastels creates a lot of fine dust, and if you're doing it at your desk, that dust is going to settle into your paper and smudge your work. Always sharpen away from your drawing.
I like to keep a small container (like an old takeaway tub) specifically for my pencil shavings. If I'm using the sandpaper method, I tap the sandpaper over the bin to clear the dust. Some artists even save this "dust" in little jars—it's essentially pure pigment that you can apply with a brush or a sponge for soft backgrounds later on. It's a great way to make sure nothing goes to waste.
At the end of the day, there isn't one "perfect" way that works for everyone. You might find that you prefer a specific type of blade or a certain grit of sandpaper. The key is to be gentle, take your time, and stop treating your pastel pencils like they're basic yellow No. 2s. Once you master the touch, you'll spend a lot less time at the trash can and a lot more time actually drawing.