For brush stroke edges, I use drafting tape or just pencil, but I don't mark anywhere near the printing area but rather the edges of the paper. I just use the tick marks on the edges to guide my eye to where I need to reach to with the brush. The drafting tape works well to define the coated area and keep the coated area about the same size each time.
Originally Posted by buggy
The approach will vary depending on how wide the brushed area is. I may have a piece of paper that is an inch or so bigger than the negative that is used as a template. I tape around it, coat the paper, peel off the tape and then go back and feather just the outside edges to give the free brush look, but get a well defined coated area to maintain speed and density of the print by keeping the coated area uniform from print to print.
Using that same technique, you can give your print well define black borders by simply not brushing the extra coated area.
The drafting tape comes in several widths for use with various sized prints. Using tape on some papers, like using the wrong brush, can lead to lift off of the paper. I also use it to hold down the corners of the paper during coating.