just in case anyone hasn't thought of it already,
if you don't have proper stencil making facilities and need a stencil quickly,
try etching thin brass sheet..
I only use it on small boards, up to about A6 size
produced by the same toner transfer process I use for pcbs..
I've used a brass stencil for several thousand boards with no signs yet of wear..
5 thou thickness seems to work well, not too much paste and stiff enough to not need a frame
Mega sell photoresist coated brass :
http://megauk.com/brass_sheet.php
I think I have some somewhere - been meaning to try it for ages...