The Utility Knife

The utility knife is a very important tool for the home remodeler. There are two types.
Fixed Blade and Adjustable.
The knife on top is an adjustable. I don’t recommend an adjustable at all. What happens is when you are
scoring sheetrock or other material the blade will get caught in your
material and jerk itself out to its full length with unpredictable
results.
The top knife has one of the few remaining slotted screws used on anything left. This has presented problems for years, as the screw slot is dime thick, but too deep to get a dime in it. So you need to carry a reasonably large flat screwdriver in your kit for feeding this.  It is a PITA, and I am all about easy.

The bottom knife is a fixed blade. Notice the large thumbscrew for opening and closing? One of the design triumphs of the 20th century!

This is a Grabber, made by the folks who make a large percentage of drywall screws on the planet. Found in Drywall Speciality stores. It has checkering(that diamond pattern on the handle),so that it does not slip easily,  is hinged on the backside with a spring inside to pop the case open, and not fly apart like other knives.
It uses standard utility blades. You can extend the life of the blade with a small sharpening stone.  It also sharpens carpenter pencils quite nicely.

Note: Always try to cut away from your body, as utility blades are quite sharp and can cut quite fast and deep. If you can’t take your time and be careful.