About a year ago I picked up a tool called the Butt-taper. It puts a bevel into the butt joint and you run 1/2" wide tape to get a 6" finished width. I do a lot of repair work, putting in a 2'x 2' patch type, and this has saved me at least at a minimum, materials money on small work. I've used the 'OSB butt joint backer technique' instead of on the stud method for quite some time now and found that to be a godsend! I have over time bid larger jobs and tried to put the cost of the backers on the market that bevel the board to minimize the width of the butt joint finish. But I can't be competitive cause of the cost. The butt-taper was a one time investment and I'm sold on it. I was just wondering what experiences others have had. If you've used other products, what are they and are they cost effective? Today with houses having mega windows and extreme lighting, shadowing from wide butts are a big issue.