• Pencils are graded according to the hardness or softness of the lead.
• The hardest pencil is 9H grade and the softest pencil is 7B grade.
• Selection of the grade of pencils depends on the type of line work required and the paper on which it is used.
• Softer lead pencils are used to produce thicker and darker line work, but they wear out quickly.
• Medium grades of H, and 2H are used for general line work as well as for lettering.
• Harder grade leads produce lighter and thinner lines.
• Most construction line work is done with 4H, 5H, and 6H pencil leads, producing thin but also sufficiently dark by exerting pressure.
• Depending upon the individual's touch and the style of writing, the right pencil may be selected.