g'day lucky
a black border can also be created by burning a black border after the print exposure is made
e.g if making an 8 x10 image, get a piece of black, thin cardboard, cut to something less than 8 x10 (i've found that a 3mm border is perfect for most sizes up to say 12x16), after the print exposure is made lay this black card over the exposed paper leaving a border all round, remove the neg carrier and give a 'burning' exposure of light of the same duration, process as normal
in fact don't be afraid to experiment with pieces of black card, just remember where light falls on the paper you get black, where the paper is shaded you get white
you don't need fancy easels or masks, just have a go with the cardboard