B9 is the softest and darkest. 9H is the lightest and hardest graphite pencil. So a B6 is softer and darker than a B2. An 6H is harder and lighter than a 2H and much harder and lighter than a HB or a B pencil.
Softer pencils make darker marks since more of the material is released. Therefore, a "4H" pencil will produce lighter marks than an "2H" pencil while a "4B" pencil will make darker marks than a "2B" pencil.
So a B6 is softer and darker than a B2. An 6H is harder and lighter than a 2H and much harder and lighter than a HB or a B pencil. Sometimes you can find an F pencil which is a slightly harder version of HB, meaning you can sharpen it to an even finer point. There is no need to have all these types of graphite pencils.
Today, however, most pencils using the HB system are designated by a number such as 2B, 4B or 2H to indicate the degree of hardness. For example, a 4B would be softer than a 2B and a 3H harder than an H.
For graphite drawing pencils on the market, the lightest is 6H, while the darkest available is 8B. The higher the number in each grade, the lighter or darker it is. So a 6H will be lighter and harder than a 2H, and a 8B will be much darker and softer than a 2B. F and HB are middle-grade pencils.
The degree of hardness of a pencil is printed on the pencil.
B stands for "black". These pencils are soft. H stands for "hard". HB stands for "hard black", which means "medium hard". F stands for "firm".
An F pencil is not lighter than an H pencil. The F pencil is one step beneath the H pencil on the blackness scale. On the numeric scale, H is referred to as number 3, HB is number 2 and since F is in between these two it is considered number 2.5.
HB pencils are most commonly used for writing, and are a staple in schools for exams and penmanship. Some people prefer writing with a 2B pencil as it has a darker lead for writing and calligraphy. If you're using a mechanical pencil, go for 0.5mm or 0.7mm lead.
Numbers are then used to indicate the degree of softness - the higher the number the softer the lead and the blacker the mark. For example, a 2B lead is softer than a B lead and will produce a blacker mark.
As you can see in the image, the higher the H value, the lighter the result but the finer the point, while at the other end, the higher the B value, the darker the blackness of the graphite and wider the point.
The difference gets more noticeable down the line, however, exposing a core limitation of graphite pencils: they only go so dark. The graphite-only 8B really isn't much darker than the 6B, which isn't much darker than the 4B.
B pencils are softer and leave more graphite on the paper, meaning they are darker. F means Fine Point. This is quite a hard pencil and is easy to keep sharp, but generally a bit too hard for general drawing.
H, or hard, leads are tightly compacted and contain more filler, which causes them to make the lightest lines, as only a tiny amount of graphite is released when the pencil is used. It takes a lot of pressure to make a darker line with pencils in the H category.
What is an 'H' pencil used for? Drawing Pencils are graded with letters and numbers according to their hardness and relative darkness. They go from H6 being the hardest and lightest to 6B being the softest and darkest. HB is the very middle.
Even though 9B is the softest pencil, you can still use it to draw an entire portrait with values ranging from medium grey to black. Although, it would be a big challenge since it would require a lot of effort to keep from shading your drawing too dark.
Pencils above number two are filled with harder graphite and tend to have lighter markings and are frequently used in draughting pencils, often used by architects and designers. A number two pencil on the numeric scale is roughly equivalent to an HB pencil on the international scale.
The 6B pencil is good for very dark areas, but it's very soft and blunts quickly, so it's difficult to use for detail and tends to look grainy, skimming over the surface of the paper. Burnished graphite—shaded very heavily—can look very shiny.
Graphite pencils with hardness degrees of 3B to 8B are ideal for artistic, pictorial drawing with their very soft to extra soft, very black graphite. Graphite pencils H, F, HB, B, and 2B are ideal for drawing and writing with our B (soft black) pencil being equivalent to the traditional No. 2 pencil.
2B is harder than 4B and 4B is harder than 6B. However, these are all on the soft side (B). The following is the standard scale. Hardest is on the left, softest on the right: 10H,9H,8H,7H,6H,5H,4H,3H,2H,H,F,HB,B,2B,3B,4B,5B,6B,7B,8B,8B,10B.
If you are sketching use a medium (HB) or hard pencil (2H – 9H) for technical drawing and small details. The soft pencils (2B – 9B) are used to provide deep darks and shadows.
0.3mm leads are the thinnest of the lead sizes currently available. As this size is generally used for technical drawings and finer details they are usually available in HB or harder, but softer graded leads can be found. The 0.3mm HB was hard to write with, as there was no give in curves.