I decided to try my hand at handcut dovetails. This marking jig has a 1:7 ration. I made it out of 1/4" hardboard that is smooth on both sids. I cut 2 pieces into 2.5" squares. I then cut my angles on one piece and cut a dadao in the other. Then I glued together making sure they were at 90 degrees. If you look at the youtube of Rob Cosman's version ($24.95 on his web sight) you can see how to use it. Laying out for the cuts is sooooo easy with this jig.