Paper tape and joint compound are the only two supplies you need to finish new drywall until you come to the outside corners. Because they are vulnerable to impact, you have to cover them with rigid beading, which gives the wall a sharp, hard edge. If you prefer rounded edges, you can substitute bullnose beading. Vinyl and paper bullnose are alternatives to the original galvanized metal, and each has its advantages.
Out with Metal Beading
Both vinyl and paper beading avoid the problems associated with metal bullnose. You have to use nails or screws to attach metal bullnose to the wall, and these fasteners make dimples in the metal that can be hard to cover with joint compound. Moreover, nails can pop out. These fasteners aren't necessary when using vinyl or paper beading. Moreover, neither of these materials sustains dents like metal, and they won't kink during the installation process. Because they aren't metal, they hold paint without the need for an application of special primer.
It Isn't Really Paper
Paper bullnose beading has a core that's as hard as the vinyl variety, but it's covered with conventional paper tape, which is why people call it paper beading. The edges of the paper extend for an inch on either side of the core, and you stick them to the wall with joint compound as if you were taping a flat joint. To cover a corner, you spread a layer of mud on both walls, press the beading into the mud and scrap the paper flat with a drywall knife. You then topcoat with two or more layers of mud.
The Glue-On Alternative
Vinyl beading -- which has a hard plastic core and plastic edges -- is the easiest of the three types of beading to hang. It's designed to be used with spray adhesive that sticks it solidly to the wall and prevents it from moving when you mud the edges. To install it, you spray both walls with the adhesive -- which comes in an aerosol can -- and simply press the beading onto the adhesive. You then topcoat the edges with two or three layers of mud in the same way as you finish the other types of beading.
Making the Choice
Cost isn't a factor when choosing between vinyl and paper bullnose beading, because both types are comparable in price. If you are a proficient taper, you may prefer the paper variety, because installing it is so much like taping a flat seam. If you find taping challenging, though, you may appreciate being able to simply glue the beading to the wall. Besides this, vinyl beading has another advantage over paper: it comes with glue-on transition pieces for baseboard and other types of molding. You have to make your own transitions when using paper tape, and this can be problematic.