Pencil Graphite Hardness Explained

Why do some pencils write and draw darker than others? It’s not as complicated as you may think. Graphite hardness results in very different effects when writing and drawing. If you look at a lead grade swatch, like in the image below, you’ll see that the spectrum from lightest to darkest moves from numbers 9H to 9B (10H to 10B offered in some cases). There are two scales used globally to measure a pencil’s grade, which is determined by the graphite core.

Before understanding how graphite hardness works, it’s important to understand that graphite pencil cores comprise two main attributes - graphite and clay. Most pencils have binders like polymer or wax, but graphite and clay are the two components you need to consider. The lightness or darkness of the mark left on a piece of paper by a pencil all depends on the ratio of graphite to clay. More clay = harder and lighter. More graphite = darker and softer. By changing up the mixtureand ratio, pencil manufacturers can influence how light or dark the marks will be.

Pencil manufacturers worldwide use a grading scale to measure hardness, softness, lightness, and darkness. There are both American and European systems of measurement. Graphite hardness is measured in both numeric scale and letters, otherwise known as the HB scale. Long story short, Americans use the numerical scale (1-4) and Europeans use the letters “H” and “B.” Here’s a good rule of thumb: B grades mean more graphite, which leaves darker, bolder marks. H means more clay, leaving finer, lighter marks than don’t smudge as easily as their darker counterpart.

You’ll normally find the number or letter marked on the pencil itself, like “2” or “3.” The higher the number, the harder the writer core, and the lighter the pencil will write on the paper. The softer the pencil’s core, the darker the mark it leaves on the paper. Why? Because a higher amount of graphite materials is deposited onto the paper. While there are a number of differences between softer and harder leads, softer ones are notorious for dulling faster. They also need to be sharpened more frequently.

Now, let’s talk about the HB scale, the second graphite grading scale, used by the majority of pencil manufacturers outside of the U.S. You’ll normally find the letter “H” on any hard pencils you purchase. Other pencil manufacturers may use “B” to indicate softer lead. It’s not uncommon to see the letter “F” too, which means that you’ll get a fine point when you sharpen the pencil.

So, what about letter combinations? Let’s say a pencil is marked with HH. That would mean that the lead is extra hard, while “HB” stands for “Hard” and “Black.” HB sits in the middle of the scale.

Now comes the big question - how can you know which pencil is right for your writing? This all depends on your own creative needs. It’s all about personal preference. If you have no idea where to begin, don’t panic. Buy some different pencils and start experimenting to see what works for you.

If you’re ready to start putting the graphite grading scale to the test, let us help. We sell a broad range of high-quality Japanese and European pencils, along with high-end pencil brands from other leading stationery destinations worldwide. Our collection of quality stationery is always growing, giving you more variety and flexibility to fuel your creative needs.

Check out our catalogue of graded graphite pencils today - you never know what you might find!