A standard utility knife has a holder and a simple razor blade protruding from the handle. The most basic utility knife does not allow the user to adjust the height or length of the blade. The blade cannot retract and therefore cannot be adjusted to protect package contents.
A retractable utility knife can be adjusted to any particular length so that a package can be opened without damaging the contents inside. Usually there is a sliding button on the side or front of the knife handle that operates the utility knife blade. This sliding button allows the user to adjust the height of the blade. It also allows the blade to be concealed within the handle and provides an extra measure of safety and protection from the utility knife blade.
This is a safer utility knife design. The knife is fitted with a spring loaded design that retracts the blade when not in use. These self-retracting utility knives can be purchased with round tipped blades for added safety. They can be purchased for around $8.
A popular style of utility knife is the X-acto #1 utility knife. This knife is widely used for making crafts and in the construction of models, among other artistic and general use applications. The X-acto #1 consists of a 4 7/8-inch barrel shaped, aluminum handle with a sharp blade positioned on its tip. It is extremely lightweight for fine cutting and carving and can be purchased for around $3.
The snap-off utility knife was designed by a Japanese corporation called Olfa by the company’s founder, Mr. Okada. The snap off blades are serrated, and when the edge becomes dull the blade can be snapped off at one of the serrated points to create a new sharp blade end. Snap off utility knives can be purchased for around $8.