What Makes a No. 2 Pencil Different?

Take a quick trip down the office supply aisle at your favorite superstore and you'll see hundreds of writing supplies, including markers, crayons, highlighters, pens, and—of course—pencils. Ever since you were old enough to first grip your fingers around a pencil and scribble joyfully on a piece of paper, you've most likely used No. 2 pencils.

Teachers request them on back-to-school shopping lists each fall, just like clockwork. Standardized test instructions remind high school students to bring plenty of them to take the exam. Yes, we dutifully use No. 2 pencils without giving them a second thought. But what does that number two actually mean? Why are No. 2 pencils so special?

What Does No. 2 Even Mean?

Although modern pencil "lead" is actually a mixture of graphite and clay. Throughout Europe and in other counties across the globe, pencils are classified using a system of letters and numbers to describe how hard and how black a pencil's "lead" is.

This European system uses a range from H (for hardness) to B (for blackness) and F (a letter that was arbitrarily chosen between H and B). Standard, run of the mill pencils used for general writing purposes are classified as HB. Pencils classified consecutively as B, 2B, 3B, 45, 5B, and so on are softer, darker pencils. Working in the "opposite direction," pencils classified as F, H, 2H, 3H, 4H, and so on are lighter, harder pencils.

A different method of classifying pencils involves numbers rather than letters. This system is also widely accepted, but it's not followed by all pencil manufacturers. In the number system, basic HB pencils are classified as #2 or No. 2. This is the system generally followed in the United States, where we are so fond of No. 2 pencils.

Despite these classification systems, there is no true pencil industry standard. Most manufacturers set their own internal standards for graphite hardness. This means that a Brand ABC pencil will not necessarily leave the same mark as a Brand XYZ pencil, even if both were labeled No. 2.

What Are Other Pencils Used For?

Pencils that have numbers higher than 2 have harder "leads." They are used by engineers, architects, and draftsmen because of their harder points, which provide a greater control in the shape of the lead. Pencils that have numbers lower than 2 are often used by artists because they can help create a variety of shades and tones.

Colored pencils, which children often use to color in school, are wax-like and crafted from pigment and other fillers, rather than carbon and clay. Grease pencils, which are usually encased in peel-off paper, can write on glass, plastic, metal, and a variety of other surfaces. Watercolor pencils, used by artists, can be used by themselves to create vibrant, bold lines. These lines can then be saturated with water and spread with paint brushes.

Why Are No. 2 Pencils Usually Yellow?

Pencils are found in various colors and even patterns, but the majority of pencils in the United States are painted yellow. According to most history lessons, a brand of pencil called Koh-i-Noor, named after a famous diamond, were crafted from the world's finest graphite from the Far East. These Koh-i-Noor pencils, intended to be the best pencils in the world, were painted yellow at a time when most pencils were dark or not colored at all. Competitors copied this yellow barrel color in hopes of consumers associating their pencils with this high-quality brand; the trend stuck.

Why Do I Need a No. 2 Pencil for the SAT?

Students generally accept that No. 2 pencils are needed for standardized tests that use Scantron sheets. The first Scantron sheets were scored or "read" by feeding the sheets through a machine that measured how much light was blocked. No. 2 pencils were required to fill in the circles on the sheet because the graphite in the pencil is an opaque substance that absorbs the light that hits it.

Most modern sheets are now read by machines that measure lightness and darkness. These machines (technically) do not require the use of No. 2 pencils, but it's a good idea to use them anyway. Harder pencils may smudge easier and be harder to erase, while lighter pencils may leave lighter marks that the machine has trouble reading. Use a No. 2 pencil just to be on the safe side.