If you are using the carbon paper type stencil, you have to be very carefull with them or you will get burn through. I use them for serial numbers and other one time marks, and have found using a Q-tip with the etchant on it and clip the lead onto the damp end, and just use a dab dab dab method works prety well, if you use the pad, and hold it on for several seconds you will most likely have burn through, or a cloudiness around the mark. For etching your name or mark haveing a good stencil made is a must. I still use a stamp for my makers mark.
Dale