For production purposes, businesses that ship products in cardboard boxes typically have case sealers to automate that task. For occasional use, and for businesses that don't box product in industrial quantities, simple handheld packing tape guns are usually a perfectly adequate alternative. They're available in a few basic formats, varying in size and durability.

Loading a Standard Tape Gun

The standard style of tape gun is available from many vendors, and has a consistent structure. It consists of: a pistol grip; a spindle to hold the roll of tape, a roller to press the tape firmly to the box as it seals; and a sharp, serrated cutting edge. To load one, first locate the end of your tape. If you're working with a new roll, it should be clearly marked, otherwise you'll have to feel for it with a fingernail. Pull 1/4-inch to 1/2-inch of tape from the roll and fold it back on itself so it's easily grasped, then continue as follows:

  1. Lay the tape gun down on a flat, stable surface. Press the tape onto the spindle, with the end of the tape facing the cutter blade and the non-adhesive side facing up. 
  2. Pull the end of the tape away from the roll, and thread it between the roller and the flat metal or plastic flange that holds the tape to the roller. On better-quality models, this flange can be folded out of the way for easy loading, then flipped back into place once the tape is threaded through. 
  3. Extend the tape up past the cutting blade, keeping your fingers well clear of the cutting edge, then pull the tape back against the cutting edge to make a neat cut. The tape gun is now loaded, and you're ready to adjust its tension.

Adjusting Your Tension

In the center of the tape gun's spindle, most models have a nut that can be adjusted to increase or decrease the tension as the tape unspools from its roll. If the tension is too loose, the tape may not develop enough tension to adhere properly to your box. If it's too tight, it may require an irritatingly strong pull to dispense at all. To test your tension, dispense a test strip of tape onto a box. Tighten the nut clockwise, or loosen it counterclockwise, if the tape seems too loose or too tight, and dispense another strip. Repeat, until the tape adheres nicely to the box but doesn't require the user to apply excessive force.

Choice of Tape and Tape Gun

Before you purchase your tape guns, take a moment to consider the size and weight of boxes you'll be sealing. Consumer-focused models and entry-level industrial models usually accept packing tape that's only 2 inches wide. This is fine for light-duty use, but for large boxes – those exceeding 24 inches in any dimension – or boxes that will hold heavier products, you might sometimes need to use tape that's 3 or even 4 inches wide to secure the box properly. You can use 2-inch tape in a larger tape gun, but you can't use the wider tape effectively in a 2-inch tape gun. If you plan to have only one tape gun around the office it might be worthwhile to consider a 3-inch model for the added versatility, or if you'll have several on hand you can purchase a few 2-inch guns for general use and one or more larger models for heavier boxes.