Graphite pencils are made using a combination of graphite and filler material. The more graphite in the pencil lead, the softer the pencil. Graphite pencils are graded according to the hardness using a scale ranging from very hard, indicated with H-codes, to soft, indicated with B-codes. The higher the number the harder the H-code pencil and the softer the B-code pencil. Pencils of medium hardness are indicated by HB or F, for fine.
Watercolor pencils are color pencils made with water-soluble leads. These pencils may be used dry on damp paper for a soft, bleeding effect. With this technique, dry pencil is applied for fine lines and details after the paper is dry. Another technique with watercolor pencils is to use dry paper and wet the pencil lead before applying it to the paper. This technique lays down heavy pigment. A wet brush may be applied to pencil lines, if desired.
Wax-based color pencils are the standard for color pencil portrait work. These pencils lend themselves to a variety of art techniques, producing results that look like watercolor paintings, pastels, or other types of art. Wax-based color pencils are available in a wide array of different colors. They can be purchased in sets or individually, by color. A very important consideration when selecting wax-based color pencils is the color permanence of the pencils. Acid-free paper and fade-proof pencils are used for artwork that will last for a very, very long time.
Oil-based color pencils are used with turpentine for blending. When selecting oil-based pencils look for pencils that lay down color smoothly, without leaving bits of lead on the paper, which can result in smearing and streaking. When blending with turpentine, use a mask or work in a well-ventilated area. Protect your hands with latex gloves. One way to blend oil-based colors is with a tortillion dipped in turpentine. Select oil-based pencils that provide fade-proof color.