From Gel Pens to Highlighters, we’ve got all the writing essentials for your desktop in our Writing and Correctionrange, all available today on next day delivery from Staples. With a variety of sizes and shapes to choose from, it’s important to find a pen that comfortably fits your hand. A pen that is too small or too large can throw your grip off and make it uncomfortable to write for long periods of time. The same goes for lefties: the right pen should fit in the palm of your hand. The tip of a pen determines the viscosity of the ink on paper. Smaller pen tips, or fine tips, are used for more detailed, intricate writing while medium-sized pens are better for everyday use. A good size for a ballpoint pen is between 0.7 millimeters (fine) and 1 millimeter (medium).